javascript - 在 javascript 中使用私有(private)成员和方法

Question

var test = function(id, company){
    //public members
    this.id = id;
    this.company = company;
    //private member
    var age = 24;
    //private method
    var getAge = function(){
       return this.age;
    };
    //public method
    this.displayAge = function(){
       console.log(getAge());
    }
}

//invoking 

var t = new test(1, 'XYZ Corp');

t.displayAge(); //undefined

为什么不显示

Answer 1

由于 this.age 未定义，因此未显示。您想要年龄。