面试题

      var age =50
        let obj={
            age :20,
            sayHi(){
                console.log(this.age);
                return function(){
                    console.log(this.age);
                    
                }
                
            }
        }
        obj.sayHi()()

obj.sayHi()()可以写成

 var fn = obj.sayHi()
 fn()

打印

  console.log(fn);
  

得

则 fn()写成 window.fn() 答案为 20 50