var name = 'jack'function SayHello() {console.log(this.name + ' say hello!')}//直接执行方法，内部this指向windowSayHello()  //jack say hello!var stu = {name:'john'}//使用apply方法指定SayHello的调用对象为stu,方法中的this就指向stuSayHello.apply(stu) //john say hello!    

        var person = {name: 'jack',introduce: function(){console.log('my name is ' + this.name)}}var manager = {name: 'jone'}//此时的manager对象没有introduce，但是我们又想调用此方法。person.introduce.apply(manager)

        /* 1.数组push方法的参数是数组一个个的元素并非完整的数组 2.如果直接array1.push(array2)程序会报错3.apply要求参数是数组，这里我们就可以借用apply简化数组的追加运算。*/var array1 = [12 , "foo" , -2458]var array2 = ["Doe" , 555 , 100]; Array.prototype.push.apply(array1, array2); 

        /* 1.Math对象的max方法的参数是数组。2.数组本身没有max方法，借助Math对象的max方法，apply调用传入数组完美解决。*/var  numbers = [5, 458 , 120 , -215 ] var maxInNumbers = Math.max.apply(Math, numbers),   //458

        /*  apply接收参数为数组call接收参数为参数列表 */var  numbers = [5, 458 , 120 , -215 ]; var maxInNumbers = Math.max.apply(Math, numbers),   //458maxInNumbers = Math.max.call(Math, 5, 458, 120, -215); //458

        /* 这里给class为name的dom元素绑定了单击事件click事件只有在真正点击dom元素时候才会触发，此时回到函数中的this代表当前dom元素。*/var foo = {count: 1,clickEvent: function () {$('.name').on('click', function (event) {console.log(this.count)     //undefined
                });}}/* 通过_this = this保留this指向，回掉函数中的this依旧指向foo对象*/var foo = {count: 1,clickEvent: function () {var _this = this$('.name').on('click', function (event) {console.log(_this.count)     //1
                });}}/* 通过bind()函数绑定函数执行时this的指向。*/var foo = {count: 1,clickEvent: function () {$('.name').on('click', function (event) {console.log(this.count)     //1}).bind(this)}}