apply call bind修改this指向的区别

apply

 const obj1 = {
            name: '大郎',
            say: function() {
                console.log(this.name);
            }
        }
 const obj2 = {
     name:'老王'
 }
 pbj1.say.apply(obj2)//老王

当say中有传参时

 const obj1 = {
            name: '大郎',
            say: function(a) {
                console.log(this.name+a);
            }
        }
 const obj2 = {
     name:'老王'
 }
 //传参时需要以数组的方式传
 obj1.say.apply(obj2, ['翻墙'])//老王翻墙

call

const obj1 = {
            name: '大郎',
            say: function() {
                console.log(this.name);
            }
        }
 const obj2 = {
     name:'老王'
 }
 pbj1.say.call(obj2)//老王

当say中有传参时

 const obj1 = {
            name: '大郎',
            say: function(a) {
                console.log(this.name + a);
            }
        }
 const obj2 = {
            name: '老王'
        }
 obj1.say.call(obj2, '翻墙') //老王翻墙

bind

const obj1 = {
            name: '大郎',
            say: function() {
                console.log(this.name);
            }
        }
 const obj2 = {
     name:'老王'
 }
 const say = obj1.say.bind(obj2)//返回的是一个函数
 say()//老王

当say中有传参时

 const obj1 = {
            name: '大郎',
            say: function(a) {
                console.log(this.name + a);
            }
        }
 const obj2 = {
            name: '老王'
        }
 const say = obj1.say.bind(obj2,'翻墙')
 say()//老王翻墙

主要区别

apply和call用法上没有特别大的区别,都很好理解,但是apply在传参时需要将参数以数组的方式传进去

bind返回的是一个函数