在对象中定义的函数上取消反弹无法访问对象的上下文

const obj = {
  name: 'Alice',
  greet: () => {
    console.log(`Hello, my name is ${this.name}`);
  }
};

const greetFunction = obj.greet;
greetFunction(); // 输出: Hello, my name is undefined

const obj = {
  name: 'Alice',
  greet() {
    console.log(`Hello, my name is ${this.name}`);
  }
};

const greetFunction = obj.greet.bind(obj);
greetFunction(); // 输出: Hello, my name is Alice

const obj = {
  name: 'Alice',
  greet() {
    const self = this;
    setTimeout(function() {
      console.log(`Hello, my name is ${self.name}`);
    }, 100);
  }
};

obj.greet(); // 输出: Hello, my name is Alice

const obj = {
  name: 'Alice',
  greet() {
    console.log(`Hello, my name is ${this.name}`);
  }
};

// 错误的使用方式
setTimeout(obj.greet, 100); // 输出: Hello, my name is undefined

// 正确的使用方式
setTimeout(obj.greet.bind(obj), 100); // 输出: Hello, my name is Alice