如何在 JavaScript 中跨类访问属性

Question

I want to have two classes interact each other, but the class interaction is not as I expected. How to fix it?

class InstanceActions {

 static handleInstanceAction() {
    console.log(this);
  }
}

class main {
  constructor() {
    InstanceActions.handleInstanceAction(); // expected main, but undefined
  }
}

new main();

Answer 1

Your code as written throws a syntax error, the syntax for a static method is:

static methodName () {
  methodBody
}

So your code should be:

 class InstanceActions { static handleInstanceAction() { console.log(this); } } class main { constructor() { InstanceActions.handleInstanceAction(); // expected main, but undefined } } new main();

The result is:

class InstanceActions {

  static handleInstanceAction() {
    console.log(this);
  }
}

because you're using calling handleInstanceAction as a method of InstanceActions , so it's being treated as a plain object.

In javascript, this is controlled by the call (except for arrow functions).