The most commonly used in call javascript function

Change this point

      var obj1 = {
        name: "胖贼"
      };
      var obj2 = {
        name: "唐"
      };
      window.name = "window";

      var getName = function() {
        alert(this.name);
      };

      getName(); // window
      getName.call(obj1); // 胖贼
      getName.call(obj2); // 唐

      当执行 getName.call(obj1) 这句代码时, getName 函数体内的 this 就指向 obj1 对象 , 所以此处的

      var getName = function() {
        alert(this.name);
      };
      
     实际上相当于:
      var getName = function() {
        alert(obj1.name); // 胖贼
      };
复制代码

Reproduced in: https: //juejin.im/post/5d07506551882502ec1a7856