“将表达式结果分配给新的局部变量”的 VSCode 键盘快捷键？

Question

In Eclipse, there's this really handy shortcut, mapped to CTRL + 2 + L by default, which works when an expression is selected. What it does is to create a new local variable to hold the result of the expression. For example...

this.doSomeCalculation();

If the mouse cursor is positioned over the line above, CTRL + 2 + L will turn the line into...

double someCalculation = this.doSomeCalculation()

I find myself using this shortcut a lot when coding Java. Is there something similar available for editing Typescript in Visual Studio Code ?

Answer 1

You can assign keybinding to refactorings such as extract constant.

Here's a keybinding that binds ctrl shift e to the extract constant refactoring:

{
  "key": "ctrl+shift+e",
  "command": "editor.action.refactor",
  "args": {
    "kind": "refactor.extract.constant",
    "apply": "first"
  }
}

This keybinding will work in JavaScript and TypeScript (and in any other languages that have an extract constant refactoring)

PS Here is a slight variation for JS/TS that lets a single keybinding work for both extract type and extract constant:

{
  "key": "ctrl+shift+e",
  "command": "editor.action.refactor",
  "args": {
    "kind": "refactor.extract",
    "preferred": true,
    "apply": "first"
  }
}

Answer 2

I managed to get this working through a bit of trial and error in keybindings.json . For you I think the mapping will look something like:

[
  {
    "key": "ctrl+2 ctrl+l",
    "command": "editor.action.codeAction",
    "args": {
      "kind": "refactor.assign.variable"
    },
    "when": "editorHasCodeActionsProvider && editorTextFocus && !editorReadonly"
  }
]

I'm personally using ctrl + alt + space :

[
  {
    "key": "ctrl+alt+space",
    "command": "editor.action.codeAction",
    "args": {
      "kind": "refactor.assign.variable"
    },
    "when": "editorHasCodeActionsProvider && editorTextFocus && !editorReadonly"
  }
]

Answer 3

Almost similar thing on vscode on this link

https://code.visualstudio.com/docs/java/java-editing

It shows how to extract a part of code to local variable. It's a little diferent from eclipse. On vscode it needs to "select" the statement and then press ctrl + shift + R then pops a window where you need to select to extract to local variable.

You could configure Keyboard Shortcut to Ctr + 2 l.

Really it is not same thing but...

Answer 4

You can select an expression and then:

In Mac:

Opt + Cmd + V

In Windows:

Ctrl + Alt + V