call/apply 作用用来改变this指向两者的区别是参数的传递不同,call传递的是变量, apply传递的是数组 var obj = { name:'ghost', age:'20' } function Person(name,age){ this.name = name this.age = age this.say = function(){ console.log(this.name) } } var person =new Person("charry", 20) //charry person.say() //这里的this,谁调用指向谁 所以指向person person.say.call(obj) //ghost 这里改变过this指向,其this指向obj function Person(name, age, sex){ this.name = name this.age = age this.sex = sex } function Student(name, age ,sex, tel, grade){ Person.call(this, name, age, sex) //调用Peson的方法来实习自己的函数,这里的this指向的是Student本身 this.tel = tel; this.grade = grade } var student =