在默认情况下，运行 `npm install` 不会重新生成整个 `package-lock.json` 文件。`npm install` 主要有两个目的：

1. 在没有 `package-lock.json` 文件时，安装 `package.json` 中定义的依赖并生成一个新的 `package-lock.json` 文件。这个新生成的文件确保了未来的安装能得到相同版本的依赖，使得项目更加稳定可靠。
2. 当已经存在 `package-lock.json` 文件时，`npm install` 会依照这个文件安装确切版本的依赖，以保证所有使用该项目的开发者都有着一致的依赖树。

然而，当你添加新的包或者更新现有包的版本时，例如使用 `npm install <package>` 或 `npm install <package>@<version>`，`npm` 会更新 `package.json` 并相应地调整 `package-lock.json` 来反映新的依赖信息。这种情况下，`package-lock.json` 文件确实会被修改，但不是完全重写，而是更新或添加了相关依赖的条目。

例如，假设我正在开发一个使用 Express.js 的 Node.js 应用，并且我希望安装一个新的依赖，比如 `axios`。我会运行：

```sh
npm install axios
```

此命令会将 `axios` 添加到 `package.json` 文件中，并更新 `package-lock.json` 文件以包含 `axios` 及其所有子依赖的确切版本信息。如果我已经安装了 `axios`，但是我想要升级到一个新版本，我可以指定版本号：

```sh
npm install axios@0.21.1
```

这将会更新 `package.json` 和 `package-lock.json` 文件，以反映我所选择的 `axios` 版本。这样的更新是选择性的，并且仅针对被修改或添加的依赖部分。

如果确实需要重新生成 `package-lock.json` 文件，可以删除已有的 `package-lock.json` 文件和 `node_modules` 目录，然后运行 `npm install`，这样会基于 `package.json` 中的依赖重新创建一个新的 `package-lock.json` 文件及安装所有依赖。但在日常开发中，这通常是不必要的。

**Update 3:** As other answers point out as well, the `npm ci` command got introduced in npm 5.7.0 as additional way to achieve fast and reproducible builds in the CI context. See the [documentation](https://docs.npmjs.com/cli/ci.html) and [npm blog](https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable) for further information.

* * *

**Update 2:** The issue to update and clarify the documentation is [GitHub issue #18103](https://github.com/npm/npm/issues/18103).

* * *

**Update 1:** The behaviour that was described below got fixed in npm 5.4.2: the currently intended behaviour is outlined in [GitHub issue #17979](https://github.com/npm/npm/issues/17979#issuecomment-332701215).

* * *

**Original answer (pre-5.4.2):** The behaviour of `package-lock.json` was changed in [npm 5.1.0](https://github.com/npm/npm/releases/tag/v5.1.0) as discussed in [issue #16866](https://github.com/npm/npm/issues/16866). The behaviour that you observe is apparently intended by npm as of version 5.1.0.

That means that `package.json` can override `package-lock.json` whenever a newer version is found for a dependency in `package.json`. If you want to pin your dependencies effectively, you now must specify the versions without a prefix, e.g., you need to write them as `1.2.0` instead of `~1.2.0` or `^1.2.0`. Then the combination of `package.json` and `package-lock.json` will yield reproducible builds. To be clear: `package-lock.json` alone no longer locks the root level dependencies!

Whether this design decision was good or not is arguable, there is an ongoing discussion resulting from this confusion on GitHub in [issue #17979](https://github.com/npm/npm/issues/17979). (In my eyes it is a questionable decision; at least the name `lock` doesn't hold true any longer.)

One more side note: there is also a restriction for registries that don’t support immutable packages, such as when you pull packages directly from GitHub instead of npmjs.org. See [this documentation of package locks](https://docs.npmjs.com/files/package-locks) for further explanation.

I've found that there will be a new version of npm [5.7.1](https://github.com/npm/npm/releases/tag/v5.7.1) with the new command `npm ci`, that will install from `package-lock.json` only

> The new npm ci command installs from your lock-file ONLY. If your package.json and your lock-file are out of sync then it will report an error.
> 
> It works by throwing away your node\_modules and recreating it from scratch.
> 
> Beyond guaranteeing you that you'll only get what is in your lock-file it's also much faster (2x-10x!) than npm install when you don't start with a node\_modules.
> 
> As you may take from the name, we expect it to be a big boon to continuous integration environments. We also expect that folks who do production deploys from git tags will see major gains.

**Short Answer:**

*   `npm install` honors package-lock.json only if it satisfies the requirements of package.json.
*   If it doesn't satisfy those requirements, packages are updated & package-lock is overwritten.
*   If you want the install to fail instead of overwriting package-lock when this happens, use `npm ci`.

* * *

**Here is a scenario that might explain things (Verified with NPM 6.3.0)**

You declare a dependency in package.json like:

    "depA": "^1.0.0"
    

Then you do, `npm install` which will generate a package-lock.json with:

    "depA": "1.0.0"
    

Few days later, a newer minor version of "depA" is released, say "1.1.0", then the following holds true:

    npm ci       # respects only package-lock.json and installs 1.0.0
    
    npm install  # also, respects the package-lock version and keeps 1.0.0 installed 
                 # (i.e. when package-lock.json exists, it overrules package.json)
    

Next, you manually update your package.json to:

    "depA": "^1.1.0"
    

Then rerun:

    npm ci      # will try to honor package-lock which says 1.0.0
                # but that does not satisfy package.json requirement of "^1.1.0" 
                # so it would throw an error 
    
    npm install # installs "1.1.0" (as required by the updated package.json)
                # also rewrites package-lock.json version to "1.1.0"
                # (i.e. when package.json is modified, it overrules the package-lock.json)

Use the newly introduced

    npm ci
    

> npm ci promises the most benefit to large teams. Giving developers the ability to “sign off” on a package lock promotes more efficient collaboration across large teams, and the ability to install exactly what is in a lockfile has the potential to save tens if not hundreds of developer hours a month, freeing teams up to spend more time building and shipping amazing things.

[Introducing `npm ci` for faster, more reliable builds](https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable)

Use the `npm ci` command instead of `npm install`.

"ci" stands for "clean install".

It will install the project dependencies based on the package-lock.json file instead of the lenient package.json file dependencies.

It will produce identical builds to your team mates and it is also much faster.

You can read more about it in this blog post: [https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable](https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable)

Why does "npm install" rewrite package- lock.json ?

首先，`nvm`（Node Version Manager）是一个用于管理多个Node.js版本的工具，它允许用户轻松切换和安装不同的Node.js版本。以下是使用`nvm`升级Node.js版本的步骤：

1. **安装或确认安装了 nvm**：
   要使用`nvm`升级Node.js，您首先需要确认您的系统上已经安装了`nvm`。可以通过在终端中运行以下命令来检查：

   ```
   nvm --version
   ```

   如果您还没有安装`nvm`，可以访问官方的[nvm GitHub仓库](https://github.com/nvm-sh/nvm)来查看安装说明。

2. **列出可用的 Node.js 版本**：
   要检查可用的Node.js版本，您可以使用`nvm`列出所有远程服务器上的版本：

   ```
   nvm ls-remote
   ```

   这个命令会列出所有可用的版本，包括LTS（长期支持）版本。

3. **安装新的 Node.js 版本**：
   当您决定要安装一个特定版本的Node.js时，可以使用以下命令：

   ```
   nvm install <version>
   ```

   您可以将`<version>`替换为特定的版本号，例如`14.17.0`，或者使用`node`代表最新的稳定版本：

   ```
   nvm install node
   ```

   这将安装最新的稳定Node.js版本。

4. **切换至新版本**：
   安装完新版本后，您可以使用如下命令切换到新版本：

   ```
   nvm use <version>
   ```

   类似地，将`<version>`替换为您刚才安装的版本号，或者使用`node`来选择最新安装的版本。

5. **确认新版本的 Node.js**：
   完成上述步骤后，您可以通过以下命令确认当前使用的Node.js版本：

   ```
   node --version
   ```

   这应该显示您刚才选择的版本。

6. **升级 npm（如果需要的话）**：
   某些时候，您可能还需要升级`npm`（Node包管理器）。您可以使用以下命令来升级`npm`：

   ```
   npm install -g npm
   ```

7. **设置默认 Node.js 版本**：
   如果您希望每次打开一个新的终端时都使用新版的Node.js，可以将它设置为默认版本：

   ```
   nvm alias default <version>
   ```

8. **如果有必要，重新安装全局包**：
   有时候，升级Node.js后，您可能需要重新安装全局Node包。您可以通过查看当前版本的全局包，然后在新版本中重新安装它们。

   ```
   nvm ls-remote --reinstall-packages-from=<old_version>
   ```

   将`<old_version>`替换为您之前使用的Node.js版本。

通过这些步骤，您应该能够在不影响旧版Node.js及其依赖的情况下，安全且正确地使用`nvm`升级Node.js版本。

This may work:

    nvm install NEW_VERSION --reinstall-packages-from=OLD_VERSION
    

For example:

    nvm install 6.7 --reinstall-packages-from=6.4
    

then, if you want, you can delete your previous version with:

    nvm uninstall OLD_VERSION
    

Where, in your case, NEW\_VERSION = 5.4 OLD\_VERSION = 5.0

Alternatively, try:

    nvm install node --reinstall-packages-from=current
    

Or you can update to the last long-term support version with

    nvm install lts --reinstall-packages-from=current

You can more simply run one of the following commands:

**Latest version**:

    nvm install node --reinstall-packages-from=node
    

**Stable (LTS) version**: (if currently in use)

    nvm install "lts/*" --reinstall-packages-from="$(nvm current)"
    

This will install the appropriate version and reinstall all packages from the currently used node version.

This saves you from manually handling the specific versions.

* * *

Kudos to @m4js7er for commenting about the LTS version.

> ⚡ **TWO** Simple Solutions:

To install the latest version of node and reinstall the old version packages just run the following command.

    nvm install node --reinstall-packages-from=node
    

To install the latest `lts` (long term support) version of node and reinstall the old version packages just run the following command.

    nvm install --lts /* --reinstall-packages-from=node
    

> Here's a **GIF** animation to support this answer:

> [![nvm](https://i.imgur.com/ZEvUYVo.gif)](https://i.imgur.com/ZEvUYVo.gif)

Here are the steps that worked for me for **Ubuntu** OS and using `nvm`

Go to nodejs website and get the last **LTS** version (for example the version will be: x.y.z)

    nvm install x.y.z
    # In my case current version is: 14.15.4 (and had 14.15.3)
    

After that, execute `nvm list` and you will get list of node versions installed by nvm.

Now you need to switch to the default last installed one by executing:

    nvm alias default x.y.z
    

List again or run `nvm --version` to check: [![enter image description here](https://i.stack.imgur.com/zCtUx.png)](https://i.stack.imgur.com/zCtUx.png)

**Update**: sometimes even if i go over the steps above it doesn't work, so what i did was removing the symbolic links in `/usr/local/bin`

    cd /usr/local/bin
    sudo rm node npm npx
    

And relink:

    sudo ln -s $(which node) /usr/local/bin/nodesudo && ln -s $(which npm) /usr/local/bin/npmsudo && ln -s $(which npx) /usr/local/bin/npx

if you have 4.2 and want to install 5.0.0 then

    nvm install v5.0.0 --reinstall-packages-from=4.2
    

the answer of gabrielperales is right except that he missed the "=" sign at the end. if you don't put the "=" sign then new node version will be installed but the packages won't be installed.

source: [sitepoint](https://www.sitepoint.com/quick-tip-multiple-versions-node-nvm/)

How to properly upgrade node using nvm

Bower和npm在功能上有着明显的区别，主要体现在它们各自的侧重点和使用场景上。以下是主要的区别：

1. **侧重点不同**：
   - **Bower**：Bower是一个前端包管理工具，专注于HTML、CSS、JavaScript等前端技术的库和框架的管理。Bower的特点是可以解决前端库的依赖问题，例如，当你需要引入一个前端库时，Bower可以自动下载该库所依赖的其他库。
   - **npm**：npm（Node Package Manager）起初是Node.js的包管理工具，用于管理Node.js模块。然而，随着前端工具链的发展，npm也被广泛用于前端项目中，它可以用来安装和管理项目依赖的库和工具，如React、Angular或Webpack等。

2. **项目结构**：
   - **Bower**：往往会将依赖安装到项目的`bower_components`目录下。
   - **npm**：会将依赖放入`node_modules`目录。

3. **包内容**：
   - **Bower**：通常包含的是编译后的代码，即最终将在浏览器中运行的代码。
   - **npm**：可能包含源码、编译后的代码，也可能包含命令行工具等。

4. **依赖管理**：
   - **Bower**：使用`bower.json`文件来管理项目的依赖关系。
   - **npm**：使用`package.json`文件来管理依赖，并且在npm v5之后，默认生成一个`package-lock.json`或在Yarn中的`yarn.lock`来锁定依赖版本，确保不同环境下安装的依赖版本一致。

5. **命令行接口**：
   - **Bower**：提供了一系列简单的命令来安装和管理前端库，例如`bower install`、`bower update`等。
   - **npm**：提供了更全面的命令行工具，不仅能安装和管理包，还能运行脚本，发布模块等，如`npm install`、`npm update`、`npm run`等。

6. **社区和生态**：
   - **Bower**：在早期前端开发中被广泛使用，但随着前端工具链的发展和npm的成熟，Bower的使用已经大幅减少。Bower自2017年起不再推荐使用，并且建议用户迁移到npm上。
   - **npm**：有着庞大的社区支持和丰富的模块生态。随着Node.js的流行，npm成为了JavaScript世界中最大的模块仓库。

举个例子，假设你在开发一个Web应用，需要引入jQuery和Bootstrap，使用Bower的话，你只需要运行`bower install jquery bootstrap`，Bower会将这两个库及其依赖的其他库（如jQuery可能被Bootstrap所依赖）下载到`bower_components`目录下。然而，随着工具如Webpack和npm脚本的流行，你现在更可能使用npm来管理这些依赖，通过`npm install jquery bootstrap`命令来安装，并通过Webpack这样的模块打包工具来组织这些库和你的应用代码。

总结来说，Bower和npm在设计上针对不同的问题和应用场景。随着前端工具链的不断发展，npm已经成为前后端通用的依赖管理工具，而Bower则逐渐淡出了主流的开发实践。

All package managers have many downsides. You just have to pick which you can live with.

History
-------

[npm](https://www.npmjs.org) started out managing node.js modules (that's why packages go into `node_modules` by default), but it works for the front-end too when combined with [Browserify](http://browserify.org/) or [webpack](https://webpack.js.org/).

[Bower](http://bower.io) is created solely for the front-end and is optimized with that in mind.

Size of repo
------------

npm is much, much larger than bower, including general purpose JavaScript (like `country-data` for country information or `sorts` for sorting functions that is usable on the front end or the back end).

Bower has a much smaller amount of packages.

Handling of styles etc
----------------------

Bower includes styles etc.

npm is focused on JavaScript. Styles are either downloaded separately or required by something like `npm-sass` or `sass-npm`.

Dependency handling
-------------------

The biggest difference is that npm does nested dependencies (but is flat by default) while Bower requires a flat dependency tree _(puts the burden of dependency resolution on the user)_.

A nested dependency tree means that your dependencies can have their own dependencies which can have their own, and so on. This allows for two modules to require different versions of the same dependency and still work. Note since npm v3, the dependency tree will be flat by default (saving space) and only nest where needed, e.g., if two dependencies need their own version of Underscore.

Some projects use both: they use Bower for front-end packages and npm for developer tools like Yeoman, Grunt, Gulp, JSHint, CoffeeScript, etc.

* * *

Resources
---------

*   [Nested Dependencies](http://maxogden.com/nested-dependencies.html) - Insight into why node\_modules works the way it does

This answer is an addition to the answer of Sindre Sorhus. The major difference between npm and Bower is the way they treat recursive dependencies. Note that they can be used together in a single project.

**On the [npm FAQ](https://web.archive.org/web/20150906022540/https://docs.npmjs.com/misc/faq#why-can-t-npm-just-put-everything-in-one-place-like-other-package-managers):** (archive.org link from 6 Sep 2015)

> It is much harder to avoid dependency conflicts without nesting dependencies. This is fundamental to the way that npm works, and has proven to be an extremely successful approach.

**On [Bower](http://bower.io/) homepage:**

> Bower is optimized for the front-end. Bower uses a flat dependency tree, requiring only one version for each package, reducing page load to a minimum.

In short, npm aims for stability. Bower aims for minimal resource load. If you draw out the dependency structure, you will see this:

npm:

    project root
    [node_modules] // default directory for dependencies
     -> dependency A
     -> dependency B
        [node_modules]
        -> dependency A
    
     -> dependency C
        [node_modules]
        -> dependency B
          [node_modules]
           -> dependency A 
        -> dependency D
    

As you can see it installs some dependencies recursively. Dependency A has three installed instances!

Bower:

    project root
    [bower_components] // default directory for dependencies
     -> dependency A
     -> dependency B // needs A
     -> dependency C // needs B and D
     -> dependency D
    

Here you see that all unique dependencies are on the same level.

**So, why bother using npm?**

Maybe dependency B requires a different version of dependency A than dependency C. npm installs both versions of this dependency so it will work anyway, but Bower will give you a _conflict_ because it does not like duplication (because loading the same resource on a webpage is very inefficient and costly, also it can give some serious errors). You will have to manually pick which version you want to install. This can have the effect that one of the dependencies will break, but that is something that you will need to fix anyway.

So, the common usage is Bower for the packages that you want to publish on your webpages (e.g. _runtime_, where you avoid duplication), and use npm for other stuff, like testing, building, optimizing, checking, etc. (e.g. _development time_, where duplication is of less concern).

**Update for npm 3:**

npm 3 still does things differently compared to Bower. It will install the dependencies globally, but only for the first version it encounters. The other versions are installed in the tree (the parent module, then node\_modules).

*   \[node\_modules\]
    *   dep A v1.0
    *   dep B v1.0
        *   dep A v1.0 (uses root version)
    *   dep C v1.0
        *   dep A v2.0 (this version is different from the root version, so it will be an nested installation)

For more information, I suggest reading the [docs of npm 3](https://docs.npmjs.com/how-npm-works/npm3-dupe)

**TL;DR: The biggest difference in everyday use isn't nested dependencies... it's the difference between modules and globals.**

I think the previous posters have covered well some of the basic distinctions. (npm's use of nested dependencies is indeed very helpful in managing large, complex applications, though I don't think it's the most important distinction.)

I'm surprised, however, that nobody has explicitly explained one of the most fundamental distinctions between Bower and npm. If you read the answers above, you'll see the word 'modules' used often in the context of npm. But it's mentioned casually, as if it might even just be a syntax difference.

But this distinction of **modules vs. globals** (or modules vs. 'scripts') is possibly the most important difference between Bower and npm. _The npm approach of putting everything in modules requires you to change the way you write Javascript for the browser, almost certainly for the better._

### The Bower Approach: Global Resources, Like `<script>` Tags

At root, Bower is about loading plain-old script files. Whatever those script files contain, Bower will load them. Which basically means that Bower is just like including all your scripts in plain-old `<script>`'s in the `<head>` of your HTML.

So, same basic approach you're used to, but you get some nice automation conveniences:

*   You used to need to include JS dependencies in your project repo (while developing), or get them via CDN. Now, you can skip that extra download weight in the repo, and somebody can do a quick `bower install` and instantly have what they need, locally.
*   If a Bower dependency then specifies its own dependencies in its `bower.json`, those'll be downloaded for you as well.

But beyond that, _Bower doesn't change how we write javascript_. Nothing about what goes inside the files loaded by Bower needs to change at all. In particular, this means that the resources provided in scripts loaded by Bower will (usually, but not always) still be defined as _global variables_, available from anywhere in the browser execution context.

### The npm Approach: Common JS Modules, Explicit Dependency Injection

All code in Node land (and thus all code loaded via npm) is structured as modules (specifically, as an implementation of the [CommonJS module format](http://wiki.commonjs.org/wiki/Modules), or now, as an ES6 module). So, if you use NPM to handle browser-side dependencies (via Browserify or something else that does the same job), you'll structure your code the same way Node does.

Smarter people than I have tackled the question of 'Why modules?', but here's a capsule summary:

*   Anything inside a module is effectively _namespaced_, meaning it's not a global variable any more, and you can't accidentally reference it without intending to.
*   Anything inside a module must be intentionally injected into a particular context (usually another module) in order to make use of it
*   This means you can have multiple versions of the same external dependency (lodash, let's say) in various parts of your application, and they won't collide/conflict. (This happens surprisingly often, because your own code wants to use one version of a dependency, but one of your external dependencies specifies another that conflicts. Or you've got two external dependencies that each want a different version.)
*   Because all dependencies are manually injected into a particular module, it's very easy to reason about them. You know for a fact: _"The only code I need to consider when working on this is what I have intentionally chosen to inject here"_.
*   Because even the content of injected modules is _encapsulated_ behind the variable you assign it to, and all code executes inside a limited scope, surprises and collisions become very improbable. It's much, much less likely that something from one of your dependencies will accidentally redefine a global variable without you realizing it, or that you will do so. (It _can_ happen, but you usually have to go out of your way to do it, with something like `window.variable`. The one accident that still tends to occur is assigning `this.variable`, not realizing that `this` is actually `window` in the current context.)
*   When you want to test an individual module, you're able to very easily know: exactly what else (dependencies) is affecting the code that runs inside the module? And, because you're explicitly injecting everything, you can easily mock those dependencies.

To me, the use of modules for front-end code boils down to: working in a much narrower context that's easier to reason about and test, and having greater certainty about what's going on.

* * *

It only takes about 30 seconds to learn how to use the CommonJS/Node module syntax. Inside a given JS file, which is going to be a module, you first declare any outside dependencies you want to use, like this:

`var React = require('react');`

Inside the file/module, you do whatever you normally would, and create some object or function that you'll want to expose to outside users, calling it perhaps `myModule`.

At the end of a file, you export whatever you want to share with the world, like this:

`module.exports = myModule;`

Then, to use a CommonJS-based workflow in the browser, you'll use tools like Browserify to grab all those individual module files, encapsulate their contents at runtime, and inject them into each other as needed.

AND, since ES6 modules (which you'll likely transpile to ES5 with Babel or similar) are gaining wide acceptance, and work both in the browser or in Node 4.0, we should mention a [good overview](https://24ways.org/2014/javascript-modules-the-es6-way/) of those as well.

More about patterns for working with modules in [this deck](http://darrenderidder.github.io/talks/ModulePatterns/).

* * *

EDIT (Feb 2017): Facebook's [Yarn](http://yarnpkg.com) is a very important potential replacement/supplement for npm these days: fast, deterministic, offline package-management that builds on what npm gives you. It's worth a look for any JS project, particularly since it's so easy to swap it in/out.

* * *

EDIT (May 2019) "Bower has finally been [deprecated](https://bower.io/blog/2017/how-to-migrate-away-from-bower/). End of story." (h/t: @DanDascalescu, below, for pithy summary.)

And, while Yarn [is still active](https://github.com/yarnpkg/yarn/issues/6953), a lot of the momentum for it shifted back to npm once it adopted some of Yarn's key features.

2017-Oct update
---------------

Bower has finally been [deprecated](https://bower.io/blog/2017/how-to-migrate-away-from-bower/). End of story.

Older answer
------------

[From Mattias Petter Johansson, JavaScript developer at Spotify](https://www.quora.com/Why-use-Bower-when-there-is-npm/answer/Mattias-Petter-Johansson):

> In almost all cases, it's more appropriate to use Browserify and npm over Bower. It is simply a better packaging solution for front-end apps than Bower is. At Spotify, we use npm to package entire web modules (html, css, js) and it works very well.
> 
> Bower brands itself as the package manager for the web. It would be awesome if this was true - a package manager that made my life better as a front-end developer would be awesome. The problem is that Bower offers no specialized tooling for the purpose. It offers NO tooling that I know of that npm doesn't, and especially none that is specifically useful for front-end developers. **There is simply no benefit for a front-end developer to use Bower over npm.**
> 
> We should stop using bower and consolidate around npm. Thankfully, that is what [is happening](http://www.modulecounts.com/):

[![Module counts - bower vs. npm](https://i.stack.imgur.com/HLBsP.png)](https://i.stack.imgur.com/HLBsP.png)

> With browserify or webpack, it becomes super-easy to concatenate all your modules into big minified files, which is awesome for performance, especially for mobile devices. Not so with Bower, which will require significantly more labor to get the same effect.
> 
> npm also offers you the ability to use multiple versions of modules simultaneously. If you have not done much application development, this might initially strike you as a bad thing, but once you've gone through a few bouts of [Dependency hell](http://en.wikipedia.org/wiki/Dependency_hell) you will realize that having the ability to have multiple versions of one module is a pretty darn great feature. Note that npm includes a very handy [dedupe tool](https://docs.npmjs.com/cli/dedupe) that automatically makes sure that you only use two versions of a module if you actually _have_ to - if two modules both _can_ use the same version of one module, they will. But if they _can't_, you have a very handy out.

(Note that [Webpack](https://www.reddit.com/r/javascript/comments/2is81v/why_is_not_systemjs_dominating_the_field_of/cla66t3) and [rollup](https://nolanlawson.com/2016/08/15/the-cost-of-small-modules/) are widely regarded to be better than Browserify as of Aug 2016.)

Bower maintains a single version of modules, it only tries to help you select the correct/best one for you.

> [Javascript dependency management : npm vs bower vs volo?](https://stackoverflow.com/questions/15092345/javascript-dependency-management-npm-vs-bower-vs-volo/22101165#22101165)

NPM is better for node modules because there is a module system and you're working locally. Bower is good for the browser because currently there is only the global scope, and you want to be very selective about the version you work with.

What is the difference between bower and npm

在Node.js中，可以通过npm（Node包管理器）来卸载已安装的模块。卸载npm模块的基本命令格式如下：

```bash
npm uninstall <module_name>
```

这里是详细步骤和示例：

1. **全局卸载模块**：
   如果模块是全局安装的，需要使用 `-g`标志来卸载它。例如，如果您想全局卸载名为 `nodemon`的模块，您可以使用以下命令：

   ```bash
   npm uninstall -g nodemon
   ```
2. **本地卸载模块**：
   如果模块是作为项目依赖安装的，那么您可以直接在项目根目录中执行卸载命令。比如您的项目使用了 `express`，卸载它的命令如下：

   ```bash
   npm uninstall express
   ```

这将会从您的 `node_modules`目录中移除 `express`模块，并且同时更新 `package.json`和 `package-lock.json`文件中的依赖信息。

3. **保存到依赖列表中的卸载**：
   若您在安装模块时使用了 `--save`、`--save-dev`或 `--save-optional`标志，卸载时也应该考虑是否需要从相关的依赖列表中移除。例如，如果 `express`是作为开发依赖（devDependency）安装的，卸载并更新 `package.json`的命令如下：

   ```bash
   npm uninstall --save-dev express
   ```
4. **检查是否正确卸载**：
   卸载后，您可以通过检查项目的 `node_modules`目录，或者使用 `npm list`命令来确认模块是否已被正确卸载。

   ```bash
   npm list
   npm list -g   # 用于检查全局模块
   ```

请注意，有时候即使卸载了一个模块，该模块的依赖可能仍然存在于 `node_modules`目录中。如果您想彻底清理不再需要的模块，可以使用如 `npm prune`的命令来移除项目中未列在 `package.json`文件中的所有模块。

以上就是在Node.js中卸载npm模块的基本步骤。


The command is simply `npm uninstall <name>`

The Node.js documents [https://npmjs.org/doc/](https://npmjs.org/doc/) have all the commands that you need to know with npm.

A local install will be in the `node_modules/` directory of your application. This won't affect the application if a module remains there with no references to it.

If you're removing a global package, however, any applications referencing it will crash.

Here are different options:

`npm uninstall <name>` removes the module from `node_modules` but does not update `package.json`

`npm uninstall <name> --save` also removes it from `dependencies`in `package.json`

`npm uninstall <name> --save-dev` also removes it from `devDependencies` in `package.json`

`npm uninstall -g <name> --save` also removes it globally

If it doesn't work with `npm uninstall <module_name>` try it globally by typing `-g`.

Maybe you just need to do it as an superUser/administrator with `sudo npm uninstall <module_name>`.

Well, to give a complete answer to this question, there are [two methods](https://docs.npmjs.com/getting-started/uninstalling-local-packages) (for example we call the installed module as module1):

1.  To remove module1 **without** changing package.json:
    
    `npm uninstall module1`
    
2.  To remove module1 **with** changing package.json, and removing it from the dependencies in package.json:
    
    `npm uninstall --save module1`
    

Note: to simplify the above mentioned commands, you can use **\-S** instead of **\--save** , and can use **remove**, **rm**, **r**, **un**, **unlink** instead of **uninstall**

I just install _stylus_ by default under my home dir, so I just use `npm uninstall stylus` to detach it, or you can try `npm rm <package_name>` out.

To uninstall the Node.js module:

    npm uninstall <module_name>
    

This will remove the module from folder _node\_modules_, but not from file _package.json_. So when we do npm install again it will download the module.

So to remove the module from file _package.json_, use:

    npm uninstall <module_name> --save
    

This also deletes the dependency from file _package.json_.

And if you want to uninstall any globally module you can use:

    npm -g uninstall <module_name> --save
    

This will delete the dependency globally.

How can I uninstall npm modules in NodeJS ?

要将Node.js和npm更新到最新的版本，需要遵循一系列步骤，这取决于您的操作系统以及您当前安装Node.js的方式。以下是一些通用的指导步骤，适用于多种操作系统：

### 使用包管理器更新

#### 对于 macOS 和 Linux 用户：

1. **使用Homebrew**（如果是macOS并且之前通过Homebrew安装）:
   安装Homebrew:
   ```sh
   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   ```
   更新Node.js:
   ```sh
   brew update
   brew upgrade node
   ```

2. **使用n或nvm**（Node.js版本管理器）:
   安装n（简化版本管理器）:
   ```sh
   npm install -g n
   ```
   使用n更新到最新的稳定版本:
   ```sh
   n stable
   ```

   或者安装nvm（Node版本管理器）:
   ```sh
   curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
   # 或者使用Wget:
   wget -qO- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
   ```
   通过nvm安装最新的Node.js版本:
   ```sh
   nvm install node # "node"是指最新版本
   nvm use node
   ```

#### 对于Windows用户：

如果你是通过Windows包管理器如Chocolatey安装的，可以使用以下命令：

```sh
choco upgrade nodejs
```

或者，您也可以使用nvm-windows，一个专为Windows环境设计的nvm版本：

```sh
nvm install latest
nvm use latest
```

### 手动更新

如果你没有使用任何包管理器，你可以手动下载最新的Node.js安装包：

1. 访问Node.js官方网站 [Node.js](https://nodejs.org/)。
2. 根据您的操作系统选择相应的安装包下载。
3. 运行下载的安装程序并遵循其指示以完成安装。

### 更新npm

通常，更新Node.js后，npm也会更新。但是，如果需要手动更新npm，可以使用以下命令：

```sh
npm install -g npm@latest
```

这会将npm更新到最新的版本。

### 验证更新

安装完毕后，您可以运行下面的命令来验证Node.js和npm的版本：

```sh
node -v
npm -v
```

这两条命令将会显示您当前的Node.js和npm版本，从而验证更新是否成功。

请记住，更新到最新版本可能会导致与旧项目的兼容性问题，因此在更新之前最好备份您的项目。此外，某些项目可能依赖于特定的Node.js版本，所以在升级到最新的版本之前，请确保阅读项目文档以避免潜在的版本冲突。

Use:

    npm update -g npm
    

See the documentation for the **[`update`](https://docs.npmjs.com/cli/update)** command:

> `npm update [-g] [<pkg>...]`
> 
> This command will update all the packages listed to the latest version (specified by the tag config), respecting semver.

Additionally, see the documentation on [Node.js and NPM installation](https://docs.npmjs.com/downloading-and-installing-node-js-and-npm) and [Upgrading NPM](https://docs.npmjs.com/try-the-latest-stable-version-of-npm).

The following original answer is from the old FAQ that no longer exists, but it should work for Linux and Mac:

> How do I update npm?
> --------------------
> 
>     npm install -g npm
>     
> 
> Please note that this command will remove your current version of npm. Make sure to use `sudo npm install -g npm` if on a Mac.
> 
> You can also update all outdated local packages by doing `npm update` without any arguments, or global packages by doing `npm update -g`.
> 
> Occasionally, the version of npm will progress such that the current version cannot be properly installed with the version that you have installed already. (Consider, if there is ever a bug in the update command.) In those cases, you can do this:
> 
>     curl https://www.npmjs.com/install.sh | sh
>     

To update Node.js itself, I recommend you use [nvm, the Node Version Manager](https://github.com/creationix/nvm).

I found this really neat way of updating Node.js on [David Walsh's blog](http://davidwalsh.name/upgrade-nodejs). You can do it by installing **[`n`](https://www.npmjs.com/package/n)**:

    sudo npm cache clean -f
    sudo npm install -g n
    sudo n stable
    

It will install the current stable version of Node.js.

* * *

But please don't use `n` anymore. I recommend using **[`nvm`](https://github.com/creationix/nvm)**. You can simply install stable by following the commands below:

    nvm ls-remote
    nvm install <version>
    nvm use <version>

Updating npm is easy:

    npm install npm@latest -g

I understand this question is for a Linux machine, but just in case anybody is looking for a Windows solution, just go to [the Node.js site](http://nodejs.org/), click the **download** button on the homepage and execute the installer program.

Thankfully, it took care of everything, and with a few clicks of the Next button, I got the latest 0.8.15 Node.js version running on my [Windows 7](https://en.wikipedia.org/wiki/Windows_7) machine.

As you may already know, _npm_ is currently bundled with Node.js. It means that if you have installed Node.js, you've already installed npm as well.

Also, pay attention to the [Node.js and npm release versions table](https://nodejs.org/en/download/releases/) that shows us approximate versions compatibility. Sometimes, versions discrepancy may cause incompatibility errors.

So, if you're a developer, it's kind of "best practice" to manage your development environment using one of the Node.js version managers.

Here is a list and usage notes of some of the most popular:

Homebrew _(macOS)_
------------------

If you're on **macOS**, you can use [Homebrew](http://brew.sh/).

_Actually, it's not just a Node.js version manager._

To install Homebrew to your Mac:

    ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
    

To install Node.js and npm using Homebrew, run:

    brew install node
    

Later, you will be able to update them using:

    brew update && brew upgrade node
    

Also, you can _switch_ between Node.js versions as well:

    brew switch node 0.10.26
    

**npm** will be _upgraded/downgraded_ automatically.

n _(macOS, Linux)_
------------------

[n](https://github.com/tj/n) is most likely to _rvm_ (Ruby Version Manager), and is used to manage Node.js and npm versions simultaneously. It is written on pure **Linux shell**, and available as an [npm module](https://www.npmjs.org/package/n). So, if you already have any Node.js version installed, you can _install/update_ the _n_ package through npm:

    npm install -g n
    

Downloading, installing and switching to Node.js and **npm** versions is as easy as:

    n 0.10.26
    n 0.8.17
    n 0.9.6
    

To download, install, and switch to the **latest** official release, use:

    n latest
    

To download, install, and switch to the latest **stable** official release, use:

    n stable
    

To switch to the previously active version (aka `$ cd -`), use:

    n prev
    

If you want to see the list of installed Node.js versions, just run `n` from your command line. The output will be something like the following:

    n
    

Output:

      0.10.26
    • 0.8.17
      0.9.6
    

Where the dot (•) means that it's a currently active version. To select another Node.js version from the list, use Up/Down arrow keys and activate using the Enter key.

To list the versions available to install:

    n lsr
    

nvm _(macOS, Linux)_
--------------------

[nvm](https://github.com/creationix/nvm) is also like rvm, even the command names and usage are very similar.

To install nvm, you can use the [installation script](https://github.com/creationix/nvm/blob/master/install.sh) (requires Git) using `cURL`:

    curl https://raw.github.com/creationix/nvm/master/install.sh | sh
    

or [Wget](https://en.wikipedia.org/wiki/Wget):

    wget -qO- https://raw.github.com/creationix/nvm/master/install.sh | sh
    

To download and install a specific Node.js and npm version, use:

    nvm install 0.10
    

Then, you can switch to the installed version, using:

    nvm use 0.10
    

Also, you can create the _.nvmrc_ file containing the version number, then switch to the specified version using the following command:

    nvm use
    

To see the list of installed Node.js versions, use:

    nvm ls
    

To list the versions available to install:

    nvm ls-remote
    

nvm-windows _(Windows)_
-----------------------

[nvm-windows](https://github.com/coreybutler/nvm-windows#node-version-manager-nvm-for-windows) is a Node.js version management utility for Windows, ironically written in [Go](https://en.wikipedia.org/wiki/Go_%28programming_language%29).

_It is not the same thing as nvm_. However, the usage as a Node.js version manager is very similar.

To install nvm-windows, it is required to uninstall any existing versions of Node.js and npm beforehand. Then, download and run the [latest installer from releases](https://github.com/coreybutler/nvm-windows/releases).

To upgrade nvm-windows, run the new installer. It will safely overwrite the files it needs to update without touching your Node.js installations.

nvm-windows runs in an Admin shell. You'll need to start PowerShell or Command Prompt as _Administrator_ to use nvm-windows.

Before using, you may also need to enable nvm-windows with the following command:

    nvm on
    

To download and install a specific Node.js and npm version, use:

    nvm install 0.12
    

Then, you can switch to the installed version, using:

    nvm use 0.12
    

If you want to see the list of installed Node.js versions, use:

    nvm list
    

To list the versions available to install:

    nvm list available

How can I update Node.js and NPM to their latest versions?

当您在`package.json`文件的依赖项列表中看到波浪号(~)和插入符号(^)，这两个符号都是用来指定npm包的版本范围的。不过，它们指定的版本范围有所不同。

### 波浪号(~)

波浪号`~`后面的版本号意味着当您运行`npm install`时，npm会安装该版本号指定的小版本（minor version）中最新的补丁版本（patch version）。也就是说，它允许安装与指定版本在小版本号相同，但是补丁版本号更高的包。

#### 例子：

如果`package.json`中的依赖项写为`"library": "~1.2.3"`，那么安装的将是1.2.x的最新版本，`x`代表该小版本中的最新补丁。因此，如果最新版本是1.2.4，您将得到1.2.4。但是它不会安装1.3.0，因为这已经是下一个小版本了。

### 插入符号(^)

插入符号`^`后面的版本号意味着当您运行`npm install`时，npm会安装与指定的主版本号（major version）相同的最新版本，但允许小版本（minor version）和补丁版本（patch version）的变动。

#### 例子：

如果`package.json`中的依赖项写为`"library": "^1.2.3"`，那么安装的将是1.x.x的最新版本，只要它不是主版本号变更（比如到2.0.0），都是允许的。所以，如果存在1.3.0或者1.4.1这样的版本，使用`^`会允许安装这些版本。

### 总结

简而言之，插入符号`^`允许更宽泛的版本升级，适用于那些遵循语义化版本（semver）并且对小版本和补丁版本的更新只包含向后兼容的更改时。波浪号`~`则更加保守，只允许补丁级别的更新，适用于对版本更新更加谨慎的场景。

在实际开发中，选择使用哪个取决于对依赖包更新的控制需求以及对三方库的信任度。如果信任库的维护者遵循严格的语义化版本原则，使用`^`可以更方便地获取功能更新和bug修复。如果希望更谨慎地更新依赖，以避免可能引入的不兼容更改，使用`~`会更保险。

See the [NPM docs](https://docs.npmjs.com/cli/v8/configuring-npm/package-json#dependencies) and [semver docs](https://docs.npmjs.com/cli/v6/using-npm/semver):

*   `~version` **“Approximately equivalent to version”**, will update you to all future patch versions, without incrementing the minor version. `~1.2.3` will use releases from 1.2.3 to <1.3.0.
    
*   `^version` **“Compatible with version”**, will update you to all future minor/patch versions, without incrementing the major version. `^1.2.3` will use releases from 1.2.3 to <2.0.0.
    

See Comments below for exceptions, in particular [for pre-one versions, such as ^0.2.3](https://stackoverflow.com/questions/22343224/whats-the-difference-between-tilde-and-caret-in-package-json#comment53973834_22345808)

I would like to add the official npmjs documentation as well which describes all methods for version specificity including the ones referred to in the question

value

desc

`~version`

Approximately equivalent to version, i.e., only accept new **patch** versions  
See [npm semver - Tilde Ranges](https://github.com/npm/node-semver#tilde-ranges-123-12-1)

`^version`

Compatible with version, i.e., accept new **minor and patch** versions  
See [npm semver - Caret Ranges](https://github.com/npm/node-semver#caret-ranges-123-025-004)

`version`

Must match version exactly

`>version`

Must be greater than version

`>=version`

Must be equal or greater than version

`<version`

Must be lesser than version

`<=version`

Must be equal or lesser than version

`1.2.x`

1.2.0, 1.2.1, etc., but not 1.3.0

`*`

Matches any version

`latest`

Obtains latest release

The above list is not exhaustive. Other version specifiers include GitHub urls and GitHub user repo's, local paths and packages with specific npm tags

### Official Docs

*   [npm docs > package.json > dependencies](https://docs.npmjs.com/cli/v7/configuring-npm/package-json#dependencies)
*   [npm docs > semver > versions](https://docs.npmjs.com/cli/v7/using-npm/semver#versions)
*   [semver (7)](http://semver.org/)

The package manager [npm](https://www.npmjs.com/) allows installing a newer package version than the one specified.  
Using tilde (`~`) gives you bug-fix releases, while caret (`^`) in addition gives you backward-compatible new functionality.

The problem is that old versions usually don't receive bug fixes, so npm uses caret (`^`) as the default for `--save`.

[![SemVer table](https://i.stack.imgur.com/JQ4ei.png)](https://i.stack.imgur.com/JQ4ei.png)

Source: ["SemVer explained - why there's a caret (^) in my package.json?"](http://bytearcher.com/articles/semver-explained-why-theres-a-caret-in-my-package-json/).

**Note** that the rules apply to versions above 1.0.0. Not every project follows semantic versioning.  
For versions 0.x.x the caret allows only _patch_ updates, i.e., it behaves the same as the tilde.  
See ["Caret Ranges"](https://github.com/npm/node-semver#caret-ranges-123-025-004).

Here's a visual explanation of the concepts:

> ![semver diagram](https://bytearcher.com/goodies/semantic-versioning-cheatsheet/wheelbarrel-with-tilde-caret-white-bg-w1000.jpg)

Source: ["Semantic Versioning Cheatsheet"](http://bytearcher.com/goodies/semantic-versioning-cheatsheet).

Semver
------

    <major>.<minor>.<patch>-beta.<beta> == 1.2.3-beta.2
    

*   Use [npm semver calculator](https://semver.npmjs.com/) for testing. Although the explanations for ^ (include everything greater than a particular version in the same major range) and ~ (include everything greater than a particular version in the same minor range) aren't a 100% correct, the calculator seems to work fine.
*   Alternatively, use [SemVer Check](http://jubianchi.github.io/semver-check/) instead, which doesn't require you to pick a package and also offers explanations.

Allow or disallow changes
-------------------------

*   Pin version: `1.2.3`.
*   Use `^` (like head). Allows updates at the second non-zero level from the left: `^0.2.3` means `0.2.3 <= v < 0.3`.
*   Use `~` (like tail). Generally freeze right-most level or set zero if omitted:
*   `~1` means `1.0.0 <= v < 2.0.0`
*   `~1.2` means `1.2.0 <= v < 1.3.0`.
*   `~1.2.4` means `1.2.4 <= v < 1.3.0`.
*   Ommit right-most level: `0.2` means `0.2 <= v < 1`. Differs from `~` because:
    *   Starting omitted level version is always `0`
    *   You can set starting major version without specifying sublevels.

All (hopefully) possibilities
-----------------------------

**Set starting major-level and allow updates upward**

    *  or "(empty string)   any version
    1                         v >= 1
    

**Freeze major-level**

    ~0 (0)            0.0 <= v < 1
    0.2               0.2 <= v < 1          // Can't do that with ^ or ~ 
    ~1 (1, ^1)        1 <= v < 2
    ^1.2              1.2 <= v < 2
    ^1.2.3            1.2.3 <= v < 2
    ^1.2.3-beta.4     1.2.3-beta.4 <= v < 2
    

**Freeze minor-level**

    ^0.0 (0.0)        0 <= v < 0.1
    ~0.2              0.2 <= v < 0.3
    ~1.2              1.2 <= v < 1.3
    ~0.2.3 (^0.2.3)   0.2.3 <= v < 0.3
    ~1.2.3            1.2.3 <= v < 1.3
    

**Freeze patch-level**

    ~1.2.3-beta.4     1.2.3-beta.4 <= v < 1.2.4 (only beta or pr allowed)
    ^0.0.3-beta       0.0.3-beta.0 <= v < 0.0.4 or 0.0.3-pr.0 <= v < 0.0.4 (only beta or pr allowed)
    ^0.0.3-beta.4     0.0.3-beta.4 <= v < 0.0.4 or 0.0.3-pr.4 <= v < 0.0.4 (only beta or pr allowed)
    

**Disallow updates**

    1.2.3             1.2.3
    ^0.0.3 (0.0.3)    0.0.3
    

**Notice**: Missing major, minor, patch or specifying `beta` without number, is the same as `any` for the missing level.

**Notice**: When you install a package which has `0` as major level, the update will only install new beta/pr level version! That's because `npm` sets `^` as default in `package.json` and when installed version is like `0.1.3`, it freezes all major/minor/patch levels.

*   [https://docs.npmjs.com/misc/semver](https://docs.npmjs.com/misc/semver)
*   [https://docs.npmjs.com/files/package.json#dependencies](https://docs.npmjs.com/files/package.json#dependencies)

As long as the first number ("major") is at least 1:

`~` locks major and minor numbers. It is used when you're ready to accept only bug-fixes (increments in the third number), but don't want any other changes, not even minor upgrades that add features.

`^` locks the major number only. It is used when you are willing to receive bug fixes (increments in the third number) and minor upgrades that add features but should not break existing code (increments in the second number). However you do not want changes that break existing code (increments in the first number).

In addition to that, `^` is [not supported](https://stackoverflow.com/questions/22270244/install-grunt-phonegap-error-no-compatible-version-found-urijs1-12-0#comment33861904_22270244) by old npm versions, and should be used with caution.

So, `^` is a good default, but it's not perfect. I suggest to carefully pick and configure the semver operator that is most useful to you.

(Revised to avoid saying "fixes" and "bug-fixes" with conflicting use of "fixes", which is confusing)

What 's the difference between tilde(~) and caret(^) in package.json ?

在使用`pnpm`作为包管理工具时，如果你有一个工作区（workspace）项目，可能需要对子包（packages）进行构建，并且这些包之间存在依赖关系。为了控制它们的构建顺序，让依赖项先被构建，你可以使用`pnpm`的几种策略。

### 1. 使用`pnpm -r`或`--recursive`

`pnpm`支持递归地在工作区中运行命令，它会自动识别包之间的依赖关系并按照正确的顺序运行。

```sh
pnpm -r --filter <filter-pattern> run <command>
```

例如，如果你想要构建所有的包，可以使用：

```sh
pnpm -r run build
```

### 2. 使用`--sort`标志

在运行`pnpm -r`时，可以添加`--sort`标志，这样`pnpm`将按照拓扑顺序执行命令，确保依赖先于依赖它们的包被处理。

```sh
pnpm -r --sort run build
```

### 3. 使用`pnpm`的`pnpm-workspace.yaml`文件

通过在`pnpm-workspace.yaml`文件中声明包的顺序，`pnpm`会在执行命令时考虑这个顺序。

```yaml
packages:
  - 'packages/utils'
  - 'packages/core'
  - 'packages/app'
```

`pnpm`会首先处理`packages/utils`，然后是`packages/core`，最后是`packages/app`。

### 4. 使用`pnpm`的过滤标志

`pnpm`支持使用过滤标志来限制命令运行的包的范围。

```sh
pnpm -r --filter "<package-name>" run build
```

你可以指定多个过滤条件来控制执行顺序。

### 5. 编写自定义脚本

如果你有特别复杂的构建需求，可以编写自定义的脚本来控制构建过程。例如，你可以使用Node.js脚本来分析`package.json`文件中的依赖，并按照你的特定需求执行构建任务。

```javascript
const { execSync } = require('child_process');
const { getWorkspaces } = require('some-workspaces-tool');

const buildPackage = (packageName) => {
  console.log(`Building ${packageName}...`);
  execSync(`pnpm run build`, { stdio: 'inherit', cwd: `packages/${packageName}` });
};

const workspaces = getWorkspaces();

// 自定义逻辑来排序和构建包
workspaces.sort(customSortFunction).forEach((workspace) => {
  buildPackage(workspace.name);
});
```

### 示例：

假设你有一个名为`@company/core`的包，它依赖于`@company/utils`。你希望在构建`@company/core`之前构建`@company/utils`。

你可以在`pnpm-workspace.yaml`中像这样指定包的顺序：

```yaml
packages:
  - 'packages/utils'
  - 'packages/core'
```

然后运行以下命令确保按照正确的顺序进行构建：

```sh
pnpm -r --sort run build
```

这会首先构建`utils`包，然后是`core`包。

使用`pnpm`的这些工具和策略，你可以有效地管理你的工作区项目的构建顺序，确保构建过程的正确性和效率。

How to control pnpm workspace build order

在使用 `pnpm` 执行命令时，如果您需要向脚本或命令传递任意参数，通常可以在命令后直接添加这些参数。但是，如果需要将参数传递给通过 `pnpm` 运行的npm脚本，则需要在参数前加上 `--` 来确保参数正确传递。

例如，如果您有一个名为 `start` 的npm脚本，您想传递一些任意参数给它，您可以这样做：

```sh
pnpm start -- --user=yourname --port=8080
```

在这个例子中，`--user=yourname` 和 `--port=8080` 是将要传递给 `start` 脚本的参数。`--` 确保 `pnpm` 会把后面的参数原封不动地传递给 `start`，而不是被 `pnpm` 本身消费。

另一个例子，如果你要使用 `pnpm exec` 命令执行一个工具，并且需要传递参数给那个工具，你通常不需要 `--`。例如：

```sh
pnpm exec some-tool --option=value
```

在这种情况下，`--option=value` 是直接传递给 `some-tool` 的参数。

请注意，pnpm的行为可能会与npm和yarn略有不同，但它们都支持使用 `--` 分隔符来传递额外的参数。

I am not sure why it throws an error. Sounds like a bug. However, this will work:

    pnpm run build --foo=bar
    

But it will not create the `npm_config_foo` env variable. It will just append the option to the executed script. So if your build script is `webpack`, then pnpm will run:

    webpack --foo=bar
    

So, it is basically like running `npm run build -- --foo=bar`. Or like running `yarn build --foo=bar`

You can read about this also in the pnpm docs: [https://pnpm.io/cli/run#options](https://pnpm.io/cli/run#options)

How to pass arbitrary argument with pnpm

当您使用 `pnpm` 来安装全局包时，默认情况下，它会将包安装到一个特定的全局目录中。但是，如果需要更改全局包的安装位置，可以通过设置环境变量来实现。

对于 `pnpm` 而言，更改全局依赖包位置的方法如下：

1. **设置环境变量**：您需要设置 `PNPM_HOME` 环境变量，来指定全局依赖包的存储位置。同时，确保将 `${PNPM_HOME}/bin` 目录添加到您的 `PATH` 环境变量中，以便可以从任何地方运行这些全局安装的包。

2. **更新配置文件**：如果您不想每次打开新的终端或会话都设置一次环境变量，可以选择将这些环境变量添加到您的 shell 配置文件中（如 `.bashrc`, `.bash_profile`, `.zshrc` 等），这样它们将自动加载。

下面是在 Unix-like 系统（如 Linux 或 macOS）上设置这些环境变量的步骤：

```sh
# 设置 PNPM_HOME 环境变量来指定全局依赖包的新位置
export PNPM_HOME="/path/to/your/global/pnpm/location"

# 将 PNPM_HOME/bin 添加到 PATH 环境变量中
export PATH="$PNPM_HOME/bin:$PATH"

# 将这些行添加到您的 shell 配置文件中，比如 .bashrc 或 .zshrc，
# 以确保每次新的终端会话都会设置这些变量。
echo 'export PNPM_HOME="/path/to/your/global/pnpm/location"' >> ~/.bashrc
echo 'export PATH="$PNPM_HOME/bin:$PATH"' >> ~/.bashrc
```

如果您使用的是 Windows 系统，则可以在“系统属性”中的“环境变量”设置或通过命令行（例如，使用 PowerShell）来设置环境变量：

```powershell
# 设置 PNPM_HOME 环境变量来指定全局依赖包的新位置
$env:PNPM_HOME="C:\path\to\your\global\pnpm\location"

# 将 PNPM_HOME\bin 添加到 PATH 现有的环境变量中
$env:PATH="$env:PNPM_HOME\bin;$env:PATH"

# 永久设置环境变量，您需要使用 Set-ItemProperty
Set-ItemProperty -Path 'HKCU:\Environment' -Name 'PNPM_HOME' -Value 'C:\path\to\your\global\pnpm\location'
[System.Environment]::SetEnvironmentVariable('PATH', "$env:PNPM_HOME\bin;$env:PATH", [System.EnvironmentVariableTarget]::User)
```

在设置了这些环境变量后，您在使用 `pnpm install -g <package>` 命令安装任何全局包时，pnpm 会将它们安装到您指定的新位置。记得替换上述命令中的 `/path/to/your/global/pnpm/location` 和 `C:\path\to\your\global\pnpm\location` 为您希望全局包安装的实际路径。

For pnpm v6, use `global-dir` instead of `pnpm-prefix`:

    pnpm config set global-dir <dir>
    

Although `<dir>` can be arbitrary, to keep the original directory structure, it should be `<your npm prefix>/pnpm-global`.

From [changelog](https://github.com/pnpm/pnpm/blob/main/packages/pnpm/CHANGELOG.md#600):

> The `pnpm-prefix` setting is removed. Use `global-dir` to specify a custom location for the globally installed packages.

Set the `pnpm-prefix` config with the desired location

    pnpm config set pnpm-prefix <dir>

How to change where pnpm installs the global packages?

迁移项目从npm到pnpm是一个可以提高包管理效率和节省磁盘空间的好方法。下面是一个详细的步骤指南：

### 1. 安装pnpm
首先，你需要在你的机器上安装pnpm。可以通过以下命令安装：

```bash
npm install -g pnpm
```

### 2. 准备迁移
在迁移之前，应该确保当前项目在npm下是处于工作状态的，这包括运行测试和确保所有依赖都是最新的。这样可以比较迁移前后的行为，确保迁移没有引入问题。

### 3. 删除node_modules和package-lock.json
pnpm使用不同的方式来安装和链接依赖，所以需要删除现有的`node_modules`文件夹以及`package-lock.json`或`npm-shrinkwrap.json`文件（如果存在的话）：

```bash
rm -rf node_modules package-lock.json
```

### 4. 使用pnpm安装依赖
现在你可以使用pnpm来安装你的项目依赖了。在你的项目根目录下运行：

```bash
pnpm install
```

这将会安装所有在`package.json`中声明的依赖，并创建一个`pnpm-lock.yaml`文件，类似npm的`package-lock.json`，但是是为了pnpm定制的。

### 5. 测试项目
安装完成后，运行项目的测试和构建脚本，确保一切工作如预期。你可以运行：

```bash
pnpm run test
pnpm run build
# 或者其他相应的脚本
```

如果遇到任何与依赖相关的问题，检查并更新`package.json`中的依赖声明，并确保它们与`pnpm-lock.yaml`匹配。

### 6. 更新CI/CD脚本
如果你的项目使用了持续集成/持续部署(CI/CD)，确保更新相关脚本以使用pnpm命令替代npm命令。

例如，你可能需要更新`.travis.yml`、`Jenkinsfile`、`GitLab-CI.yml`等配置文件。

### 7. 提交更改
提交这些更改到版本控制系统：

```bash
git add pnpm-lock.yaml
git commit -m "Migrate from npm to pnpm"
```

确保不要提交`node_modules`文件夹，通常这个文件夹应该在`.gitignore`中排除。

### 8. 通知团队成员
如果你是在团队中工作，确保通知所有成员他们需要切换到pnpm。你可以提供pnpm安装步骤和迁移后可能遇到的常见问题。

### 9. 监控生产环境
如果迁移后的项目将要部署到生产环境，密切监控应用程序以确保没有因为迁移而引起的问题。如果有问题，根据日志和指标迅速定位问题源头并修复。

以上是将项目从npm迁移到pnpm的一个基本指南。实际过程可能会根据项目的具体情况（如依赖的复杂性，自动化脚本的使用等）而有所不同。

Finally, I have made a backup of `node_modules` and rebuilt it from scratch with `pnpm` and added `concat` to have only one JavaScript source and applied `Google-compiler` to it.

The only difficulty was about `bootstrap` because it has changed a lot in two years. We need to keep the old look of it, so the command I used is `pnpm install bootstrap@3.3.7`.

After completion, the look and feel was identical but `node_modules` has grew from 8 MB to 12 MB...

You can `pnpm import` which takes your `package-lock.json` or `yarn.lock` and generates pnpm's lock file `pnpm-lock.yaml`. After that, you can `pnpm install` to install the dependencies of the project.

[documentation](https://pnpm.io/cli/import)

How to migrate a project from npm to pnpm

`pnpm install` 和 `pnpm add` 是 `pnpm` 包管理器中的两个命令，它们在某些情况下功能相似，但在其它情况下则有明显的不同：

1. **pnpm install:**
   - 这个命令在没有参数的情况下，通常用于安装或更新`package.json`中列出的所有依赖。
   - 当你在项目初次创建时或者克隆他人的项目后，可以运行`pnpm install`来安装所有必要的依赖项。
   - `pnpm install`还用于在全局安装软件包时添加`-g`标志。
   - 如果你之前安装过依赖，`pnpm install`还会更新依赖并且保持与`pnpm-lock.yaml`文件的一致性。
   - 这个命令不会修改`package.json`文件，除非你结合使用一些参数，例如`pnpm install <package-name>`。

2. **pnpm add:**
   - `pnpm add`用来添加一个或多个新的依赖到项目中。
   - 运行`pnpm add <package-name>`会将最新版本的包添加到`package.json`的依赖列表中，并且安装该依赖。
   - 可以用`pnpm add <package-name>@<version>`来指定安装特定版本的包。
   - 类似地，可以通过加`-D`或`--save-dev`来将包添加为开发依赖。
   - `pnpm add`还可以用于全局安装软件包，通过添加`-g`标志。
   - 总结来说，`pnpm add`是用来添加新依赖的，并且会修改`package.json`和`pnpm-lock.yaml`文件。

### 示例：

假设我们有一个新的项目，需要添加`react`库：

- 使用`pnpm add react`会在项目的`package.json`中添加`react`作为依赖，并且安装它。
- 如果我们已经有了`package.json`并且列出了所需的依赖，那么使用`pnpm install`会根据这个文件安装所有列出的依赖。

总的来说，`pnpm add`用于添加新的依赖，而`pnpm install`通常用于安装或更新已有的依赖。在实践中，`pnpm add`命令通常在开发过程中使用，当你需要添加新库到你的项目中；而`pnpm install`则在项目初次设置或者当你需要根据版本锁文件来同步依赖时使用。

There is not much difference between them. In most cases they are interchangeable:

`pnpm install <args?>`: without `args` it will scan and install all the modules listed in `pnpm-lock.yaml`, in case of `args` it works as `pnpm add`

`pnpm add <args>`: It will install one more package.

if choose yes i will use `pnpm add` because it is new modern syntax that supports all package managers (`npm add`, `yarn add`)

Basically as per their docs:

* * *

We need to use _**`pnpm add`**_ when we want to add a new dependency to our project

* * *

We will be needing to use _**`pnpm install`**_ when we have an existing project with the lockfile and we want to install all dependencies from the lockfile.

* * *

For more information please refer to the official docs:

[PNPM Add Docs](https://pnpm.io/cli/add)  
[PNPM Install Docs](https://pnpm.io/cli/install)

**pnpm add** : Installs **a package** and any packages that it depends on.  
**pnpm install** : is used to install all dependencies for a project.

[https://pnpm.io/cli/install](https://pnpm.io/cli/install)  
[https://pnpm.io/cli/add](https://pnpm.io/cli/add)

What the different between `pnpm install` and `pnpm add`?

要将某个依赖项添加到`pnpm`工作区，你需要遵循以下步骤：

1. **定位工作区的根目录**：
   `pnpm`工作区通常在一个包含`pnpm-workspace.yaml`文件的目录中定义。你需要先定位到这个根目录。

2. **选择要添加依赖的特定包**：
   工作区可能包含多个子项目或包，你需要确定要将依赖添加到哪个子项目中。

3. **使用`pnpm`添加依赖**：
   执行命令`pnpm add`来添加依赖项。如果你想要添加的是一个生产依赖项，你可以直接使用`pnpm add <依赖项名称>`；如果是开发依赖项，则使用`pnpm add <依赖项名称> --save-dev`。

以下是一些具体的例子：

- **为指定包添加生产依赖**：
  ```sh
  pnpm add lodash --filter <包名>
  ```
  这里`--filter <包名>`选项指定了将依赖项添加到哪个包中。如果你的工作区包名为`app`，你可以执行：
  ```sh
  pnpm add lodash --filter app
  ```

- **为指定包添加开发依赖**：
  ```sh
  pnpm add typescript --save-dev --filter <包名>
  ```
  如果你的包名为`app`，并且你想要添加TypeScript作为开发依赖项，你可以执行：
  ```sh
  pnpm add typescript --save-dev --filter app
  ```

- **为所有包添加依赖**：
  如果你想要将依赖项添加到工作区中的所有包，你可以省略`--filter`选项或使用通配符：
  ```sh
  pnpm add axios --filter '*'
  ```

请记住，使用`pnpm`时，当你在工作区的根目录中运行`pnpm add`命令并使用`--filter`选项时，依赖关系不仅会被添加到指定的包中，还会在工作区的`pnpm-lock.yaml`文件中锁定版本，确保工作区中的所有包都使用相同版本的依赖项。

So I found an answer and is using the `--filter` option.

i.e.

    # Using the exact package name
    pnpm add <package_to_add> --filter <workspace_name>
    # Or using a pattern
    pnpm add <package_to_add> --filter <prefix>/*
    

Same for run, etc...

How to add dependency to PNPM workspace?

`pnpm` 是一种包管理工具，与 `npm` 和 `yarn` 类似，但是它有自己独特的方式来管理包的存储。当你想要从本地存储中删除某个包，或者你想要强制重新下载某个包时，可以按照下面的步骤操作：

### 删除本地存储中的某个包

如果你需要从 `pnpm` 的全局存储中删除特定的包，可以使用 `pnpm store prune` 命令。这个命令会删除所有不被项目中的 `package.json` 文件依赖的包。

但是，如果你想要删除特定的包，可以手动去到 `pnpm` 的存储目录中删除对应的内容。`pnpm` 的存储目录通常在 `~/.pnpm-store`。

例如，要删除本地存储中的 `lodash` 包，你可以：

1. 找到 `lodash` 包在本地存储中的位置。
2. 直接删除该位置的相关文件和文件夹。

请注意，直接操作文件系统可能会导致 `pnpm` 的状态不一致，因此，请谨慎操作。

### 强制重新下载某个包

如果你想要强制重新下载某个包（也就是说，使 `pnpm` 忽略现有的缓存），你可以使用 `pnpm install` 命令配合 `--force` 参数。

例如，如果你想要重新下载 `express` 包，可以运行以下命令：

```sh
pnpm install express --force
```

这个命令会告诉 `pnpm` 忽略本地存储中的缓存，而是去远程仓库下载最新的 `express` 包。

再举一个实际的场景，假设你在开发一个项目，发现一个依赖的包存在问题，你可能需要删除它从而确保下次运行 `pnpm install` 时可以下载新的副本。在这种情况下，除了使用 `--force` 参数，你还可以先用 `pnpm remove` 删除该依赖，然后再次添加它：

```sh
# 删除依赖
pnpm remove lodash

# 重新添加依赖，这会下载最新的版本
pnpm add lodash
```

这样做也会导致 `pnpm` 从远程仓库下载 `lodash` 包的最新版本。

### 结论

要从 `pnpm` 的本地存储中删除包或强制重新下载，你可以使用 `pnpm store prune` 清理未使用的包，直接删除存储中的文件和文件夹，或者通过安装命令结合 `--force` 参数来忽略缓存。在实际操作中，都需要小心谨慎，确保不会影响到其他依赖或项目的正常运作。

{ My answer will cover pnpm `v2.16.2` }

Short answer: run `pnpm install --force`. (`pnpm update` might work as well)

Long answer. When you just run `pnpm install`, pnpm compares the wanted shrinkwrap file (`project/shrinkwrap.yaml`) to the current one (`project/node_modules/.shrinkwrap.yaml`). They equal in your case, so `node_modules` is not touched.

When `--force` is used, packages are reverified and relinked from the store. Reverification means that its integrity is checked. You removed a file from `jquery`, so verification will fail and the package will be reunpacked to the store and relinked to `node_modules`.

Alternatively, you could remove your project's `node_modules` and run `pnpm install`. That would also check the integrity of `jquery` before linking it to the store.

* * *

That being said, I think `pnpm install jquery` should also probably verify the integrity of jquery. We'll create an issue for this in the pnpm repo.

And maybe we can add some additional commands for reverifying every package in `node_modules` and re-unpacking all modified dependencies.

A related command currently available is [pnpm store status](https://pnpm.js.org/docs/en/pnpm-store.html#pnpm-store-status) which prints a list of mutated packages

How to remove a package from pnpm store, or force re-download it?

首先，`pnpm` 是一个快速、高效的包管理工具，它通过硬链接和符号链接的方式来节省磁盘空间，并且保证了不同项目间的依赖隔离。要确定 `pnpm` 的全局依赖库文件目录，我们可以使用 `pnpm` 命令本身来查询。  

可以通过以下命令获取 `pnpm` 的全局存储位置：

```sh
pnpm config get store-dir
```

执行这个命令后，`pnpm` 将会打印出用来存储全局依赖的文件目录路径。

举个例子，如果我在我的开发环境中运行这个命令，可能会得到类似这样的输出：

```plaintext
/home/username/.pnpm-store
```

这表明 `pnpm` 的全局依赖被存储在我的用户目录下的 `.pnpm-store` 文件夹中。

此外，了解 `pnpm` 的其他配置信息也是有用的。如果你想查看所有的 `pnpm` 配置，可以运行：

```sh
pnpm config list
```

这将列出所有的 `pnpm` 配置项，包括全局存储目录、当前的注册表以及其他相关的配置。

在实际的工作流中，知道如何查找全局存储目录可以帮助我们进行一些高级的操作，比如手动清理缓存或者调整存储位置来适用于特定的项目结构或者团队的工作流。

Nowadays you can do

    pnpm store path
    

which, according to pnpm's documentation:

> Returns the path to the active store directory.

The default locations of the store are:

*   If the `$XDG_DATA_HOME` env variable is set, then `$XDG_DATA_HOME/pnpm/store`
*   On Windows: `~/AppData/Local/pnpm/store`
*   On macOS: `~/Library/pnpm/store`
*   On Linux: `~/.local/share/pnpm/store`

Related docs: [https://pnpm.io/npmrc#store-dir](https://pnpm.io/npmrc#store-dir)

Seems like as of v3.0.1, you cannot get it. pnpm should probably update `pnpm get store` so that it returns the default location.

As of v3, the pnpm store is located at `~/.pnpm-store` by default.

You could also open the file `node_modules/.modules.yaml` in your project. It will contain a field called "store" with the location of the store that was used to hardlink packages to your project.

Update 2022:
============

As of v7, refer to @renardesque's or @nouvist's answer's below.

previously, pnpm store is located on user home folder.

    Linux   : ~/.pnpm-store
    Windows : C:\Users\YOUR_NAME\.pnpm-store
    macOS   : ~/.pnpm-store
    

but from now on ([`v7.0.0`](https://github.com/pnpm/pnpm/releases/tag/v7.0.0)), pnpm store is located on different folder. it will located on `$XDG_DATA_HOME` on Linux, and `%LOCALAPPDATA%` on Windows. take a look to [this issue](https://github.com/pnpm/pnpm/issues/2574).

    Linux   : ~/.local/share/pnpm/store (default)
    Windows : C:\Users\YOUR_NAME\AppData\Local\pnpm\store
    macOS   : ~/Library/pnpm/store
    

or, you can check where is located with [`pnpm store path`](https://pnpm.io/cli/store#path) command

**Possible locaiton:**

*   `~/.pnpm-store`  
    If project is on the **same** partition as _user home_.
*   `$partition_root/.pnpm-store`  
    If project is on **different** partition as _user home_.

**Why not just use** `~/.pnpm-store`:

*   On linux/mac, pnpm use hard link to reuse file.
*   And hard link, can be created only on the same partition.

Content-addressable store is at: C:\\Users\\username\\AppData\\Local\\pnpm\\store\\v3

Virtual store is at: node\_modules/.pnpm

How to get pnpm store directory

在面对需要切换不同版本的 PNPM 时，可以使用一些有效的工具和策略来管理这一过程。我将简要介绍几种常用的方法来实现这一目标，并且举例说明。

### 1. 使用 NVM（Node Version Manager）

NVM 是一个流行的 Node.js 版本管理工具，它也可以间接帮助管理不同版本的 PNPM，因为 PNPM 的运行依赖于 Node.js 的版本。使用 NVM 可以轻松切换 Node.js 版本，从而间接切换或重新安装不同版本的 PNPM。

**安装 NVM:**

```bash
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash
```

**使用 NVM 安装并使用特定版本的 Node.js:**

```bash
nvm install 14
nvm use 14
```

**在该 Node.js 版本下安装 PNPM:**

```bash
npm install -g pnpm
```

### 2. 使用 PNPM 的自带版本管理功能

从 PNPM 6.10.0 版本开始，PNPM 支持了内置的版本管理功能，允许用户方便地切换不同版本的 PNPM。使用 `pnpm env` 命令可以管理不同的 Node.js 和 PNPM 环境。

**列出所有可用的 PNPM 版本:**

```bash
pnpm env list --available
```

**使用特定版本的 PNPM:**

```bash
pnpm env use --pnpm <version>
```

### 3. 使用 Volta

Volta 是另一个现代的工具，专门设计用于管理 JavaScript 命令行工具和库的版本，包括 Node.js 和包管理器如 PNPM。

**安装 Volta:**

```bash
curl https://get.volta.sh | bash
```

**使用 Volta 安装并使用特定版本的 PNPM:**

```bash
volta install pnpm@6.14.2
```

### 例子

假设我们正在一个项目中使用 PNPM 6.14.2 版本，突然需要切换到 5.18.9 版本来测试一些向下兼容性问题。我们可以使用 Volta 来实现快速切换：

```bash
volta install pnpm@5.18.9
```

切换完成后，运行 `pnpm --version` 应该显示 5.18.9，表明我们已经成功切换到旧版本。

以上就是不同的方法和工具来切换和管理不同版本的 PNPM。选择哪种方法取决于个人或项目需求，以及你更习惯使用哪种工具的方式。

If you have installed pnpm through Node.js **corepack**:

    corepack enable
    

you can just run:

    corepack prepare pnpm@7.13.6 --activate
    

Here is the [doc](https://nodejs.org/api/corepack.html)

I'm also going with **node.js/corepack**. I have to jump between versions 6 and 7 for different projects.

With a recent version of node.js (16.17+) it's even easier to switch between the most recent of major versions of pnpm. For the latest of version 7 you'd type:

    corepack prepare pnpm@latest --activate
    

For the latest of version 6:

    corepack prepare pnpm@latest-6 --activate
    

It's also described in the [installation doc](https://pnpm.io/installation#using-corepack) of pnpm.

If you wish for a one-liner to use whichever pnpm version you want, use `npx`:

    npx pnpm@<version> <command>
    

For example, I have pnpm 8 installed globally but want to contribute to a project that depends on pnpm 6. This is how I do it:

    npx pnpm@6 install

PNPM（Performant NPM）是一个有效的包管理器，用于处理JavaScript项目中的依赖关系，它类似于npm和Yarn。在PNPM中，如果您想要在项目中切换使用不同版本的包，通常有以下几种方式：

### 1. 使用 `pnpm add` 命令指定版本

当您需要为项目添加一个特定版本的包时，可以使用 `pnpm add` 命令并指定版本号。例如：

```sh
pnpm add lodash@4.17.15
```

这将会安装 `lodash` 包的 `4.17.15` 版本。

### 2. 修改 `package.json` 文件

直接在项目的 `package.json` 文件中指定所需的包版本，然后运行 `pnpm install`。例如：

```json
{
  "dependencies": {
    "lodash": "4.17.15"
  }
}
```

修改完 `package.json` 之后，运行以下命令来安装指定版本的依赖：

```sh
pnpm install
```

### 3. 使用 `.npmrc` 或 `pnpm-workspace.yaml` 配置文件（对于工作区）

如果您在使用PNPM的工作区（monorepo），您可以在 `.npmrc` 或者 `pnpm-workspace.yaml` 文件中指定使用特定版本的包。

在 `.npmrc` 文件中，您可以添加如下配置以锁定特定版本：

```plaintext
lodash=4.17.15
```

在 `pnpm-workspace.yaml` 文件里，可以这样指定：

```yaml
packages:
  - 'packages/*'

dependencies:
  lodash: 4.17.15
```

### 4. 使用 `pnpm update` 命令更新版本

如果您想要更新到一个包的最新版本或一个特定范围内的版本，您可以使用 `pnpm update` 命令。例如：

```sh
# 更新到最新版本
pnpm update lodash

# 更新到特定范围的版本
pnpm update lodash@^4.17.0
```

这会把 `lodash` 更新到最新的版本，或者是符合 `^4.17.0` 范围的最新版本。

### 5. 使用版本管理工具

在维护大型项目或多个项目时，可能需要更复杂的版本管理策略。这时可以使用像 `nvm`(Node Version Manager) 这样的工具来管理不同项目使用的Node.js版本，因为不同的Node.js版本可能会自带或是兼容不同版本的包管理器。

以上就是在PNPM中切换不同版本包的几种常用方法。实际操作中，根据项目需求和团队的开发流程，选择最合适的方法来进行版本管理非常重要。

How do you switch between pnpm versions?

在 MongoDB 中，您可以使用 `$slice` 操作符来查询数组的最后一个元素。 `$slice` 可以与 `.find()` 或 `.findOne()` 方法一起使用来指定您想从数组中选择的元素的数量和位置。

如果您只想查询数组的最后一个元素，可以将 `$slice` 设置为 `-1`。以下是一个查询示例，它演示了如何选取数组字段 `arrayField` 中的最后一个元素：

```javascript
db.collection.find({}, { arrayField: { $slice: -1 } })
```

在这个例子中：

- `db.collection` 表示 MongoDB 中的集合。
- `{}` 是查询条件（空，意味着选择所有文档）。
- `{ arrayField: { $slice: -1 } }` 是投影，它指定只返回 `arrayField` 的最后一个元素。

如果您有一个具体的查询条件，并且只想针对满足该条件的文档获取数组的最后一个元素，您可以像这样组合它：

```javascript
db.collection.find({ someField: someValue }, { arrayField: { $slice: -1 } })
```

在这个例子中：

- `{ someField: someValue }` 是查询条件，用以选择具有特定 `someField` 字段值为 `someValue` 的文档。
- `{ arrayField: { $slice: -1 } }` 同样是投影，用来只选择 `arrayField` 中的最后一个元素。

请注意，`$slice` 不仅可以用来获取最后一个元素，还可以用来获取数组的子集，例如获取最后三个元素（`{ $slice: -3 }`）或跳过数组的前两个元素后取两个元素（`{ $slice: [2, 2] }`）。好的，继续补充 `$slice` 的应用，我们可以进一步讨论如何获取数组中的特定范围的元素。这在处理分页或者仅获取感兴趣的部分数据时非常有用。

比如，如果我们想要获取数组中从第二个元素开始的三个元素，我们可以设置 `$slice` 如下：

```javascript
db.collection.find({}, { arrayField: { $slice: [1, 3] } })
```

在这里：

- `[1, 3]` 表示从索引为 `1` （数组的第二个元素）开始获取，然后向后数 `3` 个元素。

此外，MongoDB 也允许你结合使用 `$elemMatch` 查询操作符和 `$slice` 来选择匹配特定条件的数组元素的子集。例如，如果你想要找到含有特定元素的文档，并且仅返回这个元素，可以这样做：

```javascript
db.collection.find({ arrayField: { $elemMatch: { key: value } } }, { 'arrayField.$': 1 })
```

在这个例子中：

- `{ arrayField: { $elemMatch: { key: value } } }` 是查询条件，它会匹配那些在数组 `arrayField` 中至少有一个元素含有键 `key` 并且值为 `value` 的文档。
- `{'arrayField.$': 1}` 是投影，它指定只返回匹配 `$elemMatch` 条件的第一个元素。

结合 `$slice` 和 `$elemMatch` 的高级用法可能会更复杂，但上述的用例展示了如何查询数组的特定部分，包括最后一个元素的常见做法。在实际的应用中，这些技术可以帮助您有效地查询和处理存储在 MongoDB 数组中的数据。

在 3.2 中这是可能的。第一个项目让 myField 只包含最后一个元素，然后在 myField 上进行匹配。

    db.collection.aggregate([
       { $project: { id: 1, myField: { $slice: [ "$myField", -1 ] } } },
       { $match: { myField: "myValue" } }
    ]);

您可以使用[$expr](https://docs.mongodb.com/manual/reference/operator/query/expr/)（3.6 mongo 版本运算符）在常规查询中使用聚合函数。

比较[`query operators`](https://docs.mongodb.com/manual/reference/operator/query/)与[`aggregation comparison operators`](https://docs.mongodb.com/manual/reference/operator/aggregation-comparison/)\_

对于标量数组

    db.col.find({$expr: {$gt: [{$arrayElemAt: ["$array", -1]}, value]}})
    

对于嵌入式数组 - 使用[`$arrayElemAt`](https://docs.mongodb.com/manual/reference/operator/aggregation/arrayElemAt/)带有点表示法的表达式来投影最后一个元素。

    db.col.find({$expr: {$gt: [{"$arrayElemAt": ["$array.field", -1]}, value]}})
    

弹簧`@Query`代码

    @Query("{$expr:{$gt:[{$arrayElemAt:[\"$array\", -1]}, ?0]}}")
    ReturnType MethodName(ArgType arg);

从 开始`Mongo 4.4`，聚合运算符[`$last`](https://docs.mongodb.com/master/reference/operator/aggregation/last-array-element/)可用于访问数组的最后一个元素：

* * *

例如，在`find`查询中：

    // { "myArray": ["A", "B", "C"] }
    // { "myArray": ["D"] }
    db.collection.find({ $expr: { $eq: [{ $last: "$myArray" }, "C"] } })
    // { "myArray": ["A", "B", "C"] }
    

* * *

或者在`aggregation`查询中：

    db.collection.aggregate([
      { $addFields: { last: { $last: "$myArray" } } },
      { $match: { last: "C" } }
    ])

使用**$slice**。

    db.collection.find( {}, { array_field: { $slice: -1 } } )
    

编辑：您可以使用它 `{ <field>: { $elemMatch: { <query1>, <query2>, ... } } }`来查找匹配项。

但它不会准确地给出您正在寻找的内容。我认为这在 mongoDB 中还不可能。

[我在](https://groups.google.com/forum/#!topic/mongodb-user/m2XB6KYs8Fw)Mongo Google 官方群组上发帖，并得到了他们工作人员的答复。看来我正在寻找的东西是不可能的。我将使用不同的模式方法。

How to query on the last element of an array inmongodb

在`pnpm`环境中，确实可以使用相似于`npm`中`npx`命令的功能。`npx`是`npm`的一个工具，允许用户运行在没有全局安装的情况下的包。`pnpm`有一个类似的命令叫`pnpx`，但从`pnpm`版本6开始，`pnpx`被标记为废弃，转而推荐直接使用`pnpm dlx`。

`pnpm dlx`命令的作用类似于`npx`，它允许你执行一个在本地未安装的npm包。这样你可以临时运行一个命令，而不需要将其添加到项目的依赖中。举个例子，如果你希望运行`create-react-app`来初始化一个新的React项目，你可以使用下面的命令：

```sh
pnpm dlx create-react-app my-app
```

这条命令将会临时安装`create-react-app`并立刻在`my-app`目录下创建一个新的React应用，而无需将`create-react-app`作为全局或项目的依赖。

使用`pnpm dlx`的好处之一是，它会使用`pnpm`的存储方式，即使是临时安装，也会利用`pnpm`的缓存和存储机制，有效地节省磁盘空间并加快后续的执行速度。

The are are two key uses of `npx`.

**Running executables inside your downloaded dependencies**

For example `npx jest`.

The pnpm equivalent is `pnpm exec jest`.

**Running executable commands in packages you want to download transiently**

For example `npx create-react-app my-app`.

The pnpm equivalent of this is `pnpm dlx create-react-app my-app`.

Note: There used to be a `pnpx` command, but it has been [deprecated](https://web.archive.org/web/20230202163724/https://pnpm.io/6.x/pnpx-cli).

Based on [PNPM Feature Comparison](https://pnpm.io/feature-comparison) the alternative to **NPX** in **PNPM** should `pnpm dlx`

Comment from the [addition of dlx](https://github.com/pnpm/pnpm/pull/3652):

> npx is also kind of deprecated and replaced by `npm exec`.

Which probably refers to npx being [deprecated as standalone package](https://github.com/npm/npx/commit/34660901133c8e890c1076d11b744ea20d9511c2#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5R1) and [inclusion into npm itself by use of `npm exec`](https://docs.npmjs.com/cli/v7/commands/npx#compatibility-with-older-npx-versions) . The [main difference](https://docs.npmjs.com/cli/v7/commands/npx#npx-vs-npm-exec) is now that

**`npm exec` supports `--` to end argument parsing** for itself and count following args to the package to be run.

Whereas **npx** requires all **args to itself** to be given **before the package** to be run and couts all following arguments to the latter.

Short answer yes. `npx create-next-app@latest --use-pnpm`

Can I use npx with pnpm?

在Typescript中删除数组中的某一项，通常有几种不同的方法。以下是一些常用的方法，每种方法都有相应的使用场景和示例。

### 1. 使用 `splice` 方法

`splice` 方法可以用来添加或删除数组中的元素。要删除特定的元素，你需要知道该元素的索引。`splice` 的第一个参数是开始修改的数组索引，第二个参数是要删除的元素数量。请注意，`splice` 是一个改变原数组的方法。

**示例：**

```typescript
let numbers = [1, 2, 3, 4, 5];
let indexToRemove = 2; // 我们想要删除数字 3，它的索引是 2
numbers.splice(indexToRemove, 1); // 从索引2的位置开始删除一个元素
console.log(numbers); // 输出: [1, 2, 4, 5]
```

### 2. 使用 `filter` 方法

如果你想要根据元素的值而不是索引来删除元素，或者需要删除满足特定条件的所有项，`filter` 方法是很好的选择。`filter` 创建一个新数组，包含通过提供的函数实现的测试的所有元素，不会改变原数组。

**示例：**

```typescript
let numbers = [1, 2, 3, 4, 5];
let valueToRemove = 3;
numbers = numbers.filter(item => item !== valueToRemove);
console.log(numbers); // 输出: [1, 2, 4, 5]
```

### 3. 使用 `slice` 方法

`slice` 方法可以用来创建数组的一个浅拷贝，从而不改变原数组。如果你知道要删除的元素的索引范围，可以使用 `slice` 来创建不包含这些元素的新数组。

**示例：**

```typescript
let numbers = [1, 2, 3, 4, 5];
let startOfNewArray = numbers.slice(0, 2); // 获取索引0到2（不包括2）的元素
let endOfNewArray = numbers.slice(3); // 获取索引3到数组末尾的元素
numbers = [...startOfNewArray, ...endOfNewArray]; // 使用展开运算符合并数组
console.log(numbers); // 输出: [1, 2, 4, 5]
```

### 4. 使用 `pop` 或 `shift` 方法

如果你想要删除数组的最后一个元素，可以使用 `pop` 方法，同样的，如果你想删除数组的第一个元素，可以使用 `shift` 方法。

**示例：**

```typescript
let numbers = [1, 2, 3, 4, 5];

numbers.pop(); // 删除数组的最后一个元素
console.log(numbers); // 输出: [1, 2, 3, 4]

numbers.shift(); // 删除数组的第一个元素
console.log(numbers); // 输出: [2, 3, 4]
```

你选择哪种方法取决于你的具体需求，比如是否需要原地修改数组、是否已知索引或者删除条件等。在实际的编码工作中，保持代码的可读性和清晰的逻辑也是非常重要的。

How do i remove an array item in typescript

在TypeScript中，将字符串转换为数字通常有两种常用的方法：使用全局的 `parseInt()` 或 `parseFloat()` 函数，以及使用一元加号运算符。下面是具体的例子：

### 使用 `parseInt()` 和 `parseFloat()`

`parseInt()` 函数用于将字符串解析为整数，而 `parseFloat()` 函数则用于解析为浮点数。

```typescript
let stringValue: string = "123";
let intValue: number = parseInt(stringValue);

// 如果字符串是浮点数表示，可以使用parseFloat来获取浮点数
stringValue = "123.456";
let floatValue: number = parseFloat(stringValue);

console.log(intValue);    // 输出：123
console.log(floatValue);  // 输出：123.456
```

`parseInt()` 函数可以接受第二个参数作为基数，以便解析不同进制的数字字符串。例如，如果你想解析十六进制的字符串，可以这样做：

```typescript
stringValue = "0xF";
intValue = parseInt(stringValue, 16);

console.log(intValue); // 输出：15
```

### 使用一元加号运算符

一元加号运算符（`+`）可以将其紧随的字符串转换成数字：

```typescript
stringValue = "123";
intValue = +stringValue;  // 一元加号

stringValue = "123.456";
floatValue = +stringValue; // 也能够处理浮点数

console.log(intValue);    // 输出：123
console.log(floatValue);  // 输出：123.456
```

这种方法很简洁，但是如果字符串不是合法的数字，则会得到 `NaN`（Not-a-Number）。

### 错误处理

在实际应用中，你通常需要处理可能发生的错误。例如，如果字符串不包含有效的数字，`parseInt()` 和 `parseFloat()` 会返回 `NaN`，而一元加号运算符也是如此。你可能需要在转换后检查结果是否为 `NaN`，并相应地处理：

```typescript
stringValue = "abc";
intValue = parseInt(stringValue);

if (isNaN(intValue)) {
    console.log("parseInt 失败，字符串不包含有效数字");
} else {
    console.log(intValue);
}

// 使用一元加号运算符时的检查
floatValue = +stringValue;

if (isNaN(floatValue)) {
    console.log("一元加号运算符转换失败，字符串不包含有效数字");
} else {
    console.log(floatValue);
}
```

在编写TypeScript代码时，考虑到类型安全和错误处理是非常重要的，以上例子都演示了如何将字符串安全地转换为数字，并如何处理潜在的错误。

[Exactly like](https://stackoverflow.com/questions/1133770/convert-a-string-to-an-integer) [in JavaScript](https://stackoverflow.com/questions/17106681/parseint-vs-unary-plus-when-to-use-which/17106702#17106702), you can use the [`parseInt`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt) or [`parseFloat`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseFloat) functions, or simply use the unary `+` operator:

    var x = "32";
    var y: number = +x;
    

All of the mentioned techniques will have correct typing and will correctly parse simple decimal integer strings like `"123"`, but will behave differently for various other, possibly expected, cases (like `"123.45"`) and corner cases (like `null`).

[![Conversion table](https://i.stack.imgur.com/QNMfI.png)](https://i.stack.imgur.com/QNMfI.png) Table taken from [this answer](https://stackoverflow.com/a/17106702/1483676)

The TypeScript way to do this would be:

    Number('1234') // 1234
    Number('9BX9') // NaN
    

as answered here: [https://stackoverflow.com/a/23440948/2083492](https://stackoverflow.com/a/23440948/2083492)

For our fellow Angular users:

Within a **template**, `Number(x)` and `parseInt(x)` throws an error, and `+x` has no effect. Valid casting will be `x*1` or `x/1`.

As shown by other answers here, there are multiple ways to do the conversion:

    Number('123');
    +'123';
    parseInt('123');
    parseFloat('123.45')
    

I'd like to mention one more thing on `parseInt` though.

When using `parseInt`, it makes sense to **always pass the radix parameter**. For decimal conversion, that is `10`. This is the default value for the parameter, which is why it _can_ be omitted. For binary, it's a `2` and `16` for hexadecimal. Actually, any radix between and including 2 and 36 works.

    parseInt('123')         // 123 (don't do this)
    parseInt('123', 10)     // 123 (much better)
    
    parseInt('1101', 2)     // 13
    parseInt('0xfae3', 16)  // 64227
    

In some JS implementations, `parseInt` **parses leading zeros as octal**:

> Although discouraged by ECMAScript 3 and forbidden by ECMAScript 5, many implementations interpret a numeric string beginning with a leading 0 as octal. The following may have an octal result, or it may have a decimal result. **Always specify a radix to avoid this unreliable behavior.**
> 
> — [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt#Octal_interpretations_with_no_radix)

The fact that code gets clearer is a nice side effect of specifying the radix parameter.

Since `parseFloat` only parses numeric expressions in radix 10, there's no need for a radix parameter here.

More on this:

*   [Why do we need to use radix? (SO Question)](https://stackoverflow.com/questions/6611824/why-do-we-need-to-use-radix)
*   [SO Answer to "What is the difference between parseInt() and Number()?"](https://stackoverflow.com/a/4090577/3861083)

Expounding on what Ryan said, TypeScript embraces the JavaScript idioms in general.

    var n = +"1"; // the unary + converts to number
    var b = !!"2"; // the !! converts truthy to true, and falsy to false
    var s = ""+3; // the ""+ converts to string via toString()
    

All the interesting in-depth details at [JavaScript Type Conversion](http://jibbering.com/faq/notes/type-conversion/).

How to convert a string to number in typescript

在TypeScript中，`unknown`和`any`类型都用于表示可能是任意类型的值，但它们的使用目的和类型安全性方面有所不同。

### `any` 类型

- **类型安全性**: `any`是TypeScript类型系统中一个逃逸舱。当你把一个值标记为`any`类型时，你基本上是在告诉编译器：“相信我，我知道我在做什么，不要对这个值做类型检查。” 这意味着你放弃了TypeScript提供的大部分类型安全性。
  
- **使用情况**: `any`类型通常用在你不想要或者不需要类型检查的场合，比如当你从一个JavaScript项目逐步迁移到TypeScript时，或者当你在处理高度动态的内容时，它可以让你快速编码，不受类型系统的限制。
  
- **例子**: 假设你有一个来自第三方库的函数，该函数返回`any`类型。
  
  ```typescript
  function getDynamicData(): any {
    // 模拟从动态数据源获取数据
    return "I could be anything!";
  }
  
  const dynamicData = getDynamicData();
  dynamicData.foo(); // 编译器不会报错，即使foo方法在运行时不存在
  ```

### `unknown` 类型

- **类型安全性**: 相比之下，`unknown`类型是TypeScript中一个更安全的选择。它表示一个值的类型未知，因此你不能只是对它做任何操作。在对`unknown`类型的值执行大多数操作之前，你需要先进行类型检查或类型断言，以确保操作是安全的。
  
- **使用情况**: 当你的函数或变量可能接受任何类型的值，但你仍然想保留TypeScript的类型检查时，使用`unknown`是一个好选择。它标志着你需要在继续操作之前验证该值的类型。
  
- **例子**: 假设你有一个函数，它接受一个`unknown`类型的参数，并检查它是否为字符串。
  
  ```typescript
  function processUnknownValue(value: unknown) {
    if (typeof value === "string") {
      console.log(value.toUpperCase()); // 类型检查确保这是安全的
    } else {
      console.log("Not a string");
    }
  }
  
  processUnknownValue("hello"); // 输出: "HELLO"
  processUnknownValue(42);      // 输出: "Not a string"
  ```

总结来说，`any`类型在TypeScript中提供了完全的灵活性，允许你在不考虑类型安全的情况下执行任何操作。而`unknown`类型提供了一种方法来表示任何可能的类型，同时仍然需要在执行操作之前进行类型检查，以保持类型安全。在实践中，优先选择`unknown`是更好的习惯，因为它能帮助你写出更安全的代码。

所有问题