在Javascript中使用"this"

Question

鉴于:

    var q = {};
    q.id = 1234;
    q.bonus = {
        'a':{
            'b':(function(){
                //i want to access q.id
                var id = this. ??? .id
            }),
        }
    };

应该是什么??? 访问q.id.

Answer 1

要q.id在函数中访问,请b使用Function.prototype.bind

var q = {};
q.id = 1234;
q.bonus = {
  'a':{
     'b': (function(){
       //i want to access q.id
       var id = this.id;
       console.log(id);
     }).bind(q),
  }
};

q.bonus.a.b();

您还可以使用Function.prototype.call来更改上下文this

q.bonus.a.b.call(q);