07-23箭头函数this指向

• 使用call方法改变this方法

    // 改变this的指向call方法
    let bar = {
      myname: 'barname',
      test:1
    }
    function fn() {
      this.myname = 'fnmyname'
    }
    fn.call(bar)
    console.log(bar)//{myname: "fnmyname", test: 1}
    console.log(bar.myname) //fnmyname
    console.log(myname) //myname is not defined

• 通过对象的方式改变函数里的this的指向

    var obj = {
      myage:18,
      objfn:function() {
         console.log(this)//{myage: 18, objfn: ƒ}
      }
    }
    obj.objfn()