What are VSCode IntelliSense features? - 面试题

VSCode IntelliSense provides intelligent code completion, parameter information, quick info and member lists, greatly improving coding efficiency.

IntelliSense Basics

Triggering IntelliSense

Manual Trigger: Ctrl+Space
Auto Trigger: Automatically display when typing
Context Trigger: Automatically display in specific contexts

IntelliSense Types

Code Completion: Auto-complete variables, functions, classes, etc.
Parameter Info: Display function parameters
Quick Info: Display type and documentation information
Member List: Display object members

Code Completion

Basic Completion

javascript
// Type partial code, IntelliSense automatically shows suggestions
console. // Shows all methods of console object

// Press Tab or Enter to accept suggestion
console.log('Hello World');

Smart Suggestions

Context-based suggestions
Prioritize most relevant suggestions
Support fuzzy matching

Completion Configuration

json
{
  "editor.quickSuggestions": {
    "other": true,
    "comments": false,
    "strings": false
  },
  "editor.suggestOnTriggerCharacters": true,
  "editor.acceptSuggestionOnEnter": "on",
  "editor.tabCompletion": "on"
}

Parameter Information

Viewing Parameter Info

Shortcut: Ctrl+Shift+Space
Function: Display function parameter types and documentation
Navigation: Use up/down arrows to switch overloads

Parameter Info Example

javascript
// Type function name then press Ctrl+Shift+Space
Math.max( // Shows parameter info: number1: number, number2: number, ...values: number[]

Quick Info

Viewing Quick Info

Shortcut: Ctrl+K, Ctrl+I
Function: Display symbol type and documentation
Hover: Hover mouse over symbol

Quick Info Example

javascript
// Hover over function name
function greet(name) {
  return `Hello, ${name}!`;
}

// Shows: function greet(name: string): string

Member List

Viewing Member List

Trigger: Type . after object name
Function: Display all members of object
Filter: Type characters to filter list

Member List Example

javascript
const obj = {
  name: 'John',
  age: 25,
  greet() {
    return `Hello, ${this.name}!`;
  }
};

obj. // Shows name, age, greet and other members

IntelliSense Configuration

Basic Configuration

json
{
  "editor.quickSuggestions": {
    "other": true,
    "comments": false,
    "strings": false
  },
  "editor.suggest.showStatusBar": true,
  "editor.suggest.maxVisibleSuggestions": 12,
  "editor.suggest.selectionMode": "always"
}

Advanced Configuration

json
{
  "editor.suggest.localityBonus": true,
  "editor.suggest.shareSuggestSelections": true,
  "editor.suggest.snippetsPreventQuickSuggestions": false,
  "editor.wordBasedSuggestions": true
}

Language-specific Configuration

JavaScript/TypeScript

json
{
  "[javascript]": {
    "editor.quickSuggestions": {
      "other": true,
      "comments": false,
      "strings": true
    }
  },
  "[typescript]": {
    "editor.quickSuggestions": {
      "other": true,
      "comments": false,
      "strings": true
    }
  }
}

Python

json
{
  "[python]": {
    "editor.quickSuggestions": {
      "other": true,
      "comments": false,
      "strings": false
    }
  }
}

IntelliSense Extensions

Installing Language Servers

TypeScript: Built-in support
Python: Pylance extension
Go: Go extension
Rust: rust-analyzer extension

Configuring Language Servers

json
{
  "typescript.suggest.autoImports": true,
  "python.analysis.autoImportCompletions": true,
  "go.useLanguageServer": true
}

Important Notes

IntelliSense depends on language servers
Large projects may affect performance
Regularly update language servers
Reasonably configure completion trigger conditions
Use code snippets to improve efficiency