如何访问在函数中的 JavaScript 函数

问题描述

在 JavaScript 中，有没有办法访问一个函数内的函数，而该函数又位于另一个函数内?

Is there any way to access a function which is inside a function, which is inside an other function in JavaScript?

function x(name, age) {
  this.name = name;
  this.age = age;


  this.a = function() {
    this.b = function() {
      return "b";
    };

    return "a";
  };
}

var xobj = new x('vin', 25);
console.log(xobj.a.b()); //error

推荐答案

你可以做的

function x(name, age){
 this.name  =name;
 this.age = age;


 this.a = function(){

		this.b = function(){
			return "b";
        };

	return "a";
  };

}


var xobj =new x('vin',25);
var xx = new xobj.a();
console.log(xx.b());

你必须声明一个 x.a() 的实例，然后调用 b

you would have to declare an instance of x.a() and then call b

当一个函数用作构造函数时(使用 new 关键字)，它的 this 绑定到正在构造的新对象.所以如果你想在函数 a() 中调用它，你必须使用 new 关键字

When a function is used as a constructor (with the new keyword), its this is bound to the new object being constructed. so If you want to call this inside the function a(), you would have to create a constructor using new keyword

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