ES6 类：将“this”绑定到嵌套函数

Question

我在一个 ES6 类中有多个嵌套函数。现在我想知道如何轻松地将类实例的 this 绑定到所有子函数。

我知道...

subfunction1.bind(this)();

...但是对于多个嵌套函数来说，这感觉像是一个尴尬的解决方案。

有人知道更优雅的解决方案吗？

class User {
  constructor(name) {
    this.name = name;
  }

  mainFunction() {
    console.log(this.name);//"Paul"
    
    //In order for the nested functions to get "this" it is needed to bind it 
    //to the subfunction as shown below. Is there an easier way to achieve
    //this for all the subfunctions at once?
    
    subfunction1.bind(this)();
    subfunction2.bind(this)();
    
    function subfunction1() {
      console.log(this.name);//"Paul"
    }
    
    function subfunction2() {
      console.log(this.name);//"Paul"
    }
  }
}
const paul = new User("Paul");
paul.mainFunction();

Answer 1

您可以使用箭头函数。它们以相当相似的方式工作。 箭头符号将 this 替换为箭头函数作用域的上下文值。

class User {
  constructor(name) {
    this.name = name;
  }

  getSummary() {
    console.log(this.name);
    const subfunction1 = () => {
      console.log(this.name);//"Paul"
    }
    const subfunction2 = () => {
      console.log(this.name);//"Paul"
    }
    subfunction1();
    subfunction2();
  }
}
const paul = new User("Paul");
paul.getSummary();

Answer 2

声明一个将在子函数范围内的局部变量，并使用它代替this。

class User {
  constructor(name) {
    this.name = name;
  }

  mainFunction() {
    const self = this;
    console.log(this.name);//"Paul"
       
    subfunction1();
    subfunction2();
    
    function subfunction1() {
      console.log(self.name);//"Paul"
    }
    
    function subfunction2() {
      console.log(self.name);//"Paul"
    }
  }
}
const paul = new User("Paul");
paul.mainFunction();