To search for methods or functions within a class in IntelliJ IDEA, use the shortcut Ctrl+F12 (on Windows/Linux) or Cmd+F12 (on macOS). This shortcut opens a pop-up window listing all methods and variables in the current class or interface.
For example, suppose you are working on a Java project and have opened a class file named UserService. If you want to quickly locate the findUserById method within this class, press Ctrl+F12, then start typing part of the method name, such as findUser. The list dynamically filters to match your input, allowing you to quickly find the findUserById method.
Additionally, if you want to search for the usage of a method across the entire project, use Ctrl+Alt+F7 (on Windows/Linux) or Cmd+Alt+F7 (on macOS) to see which files call this method. This is a useful feature, especially when working with large codebases, as it allows you to quickly locate references and usages of the method.