call(),apply()和bind()的详解使用：

obj.call(thisObj, arg1, arg2, ...);
obj.apply(thisObj, [arg1, arg2, ...]);
两者作用一致，都是把obj(即this)绑定到thisObj，这时候thisObj具备了obj的属性和方法。或者说thisObj『继承』了obj的属性和方法。绑定后会立即执行函数。
两者的不同之处：传递参数不同，call已正常参数传递，apply传参数的形式是以数组的形式传递。
bind():把obj绑定到thisObj，这时候thisObj具备了obj的属性和方法。与call和apply不同的是，bind绑定后不会立即执行。obj.bind(thisObj, arg1, arg2, ...);bind()只是起到绑定作用并不执行，只有执行才会触发obj.bind(thisObj, arg1, arg2, ...)();

     function add(a,b) {
         this.num1 = a;
         this.num2 = b;
         return num1 + num2;
     }
     function sub(a,b) {
         this.num1 = a;
         this.num2 = b;
         return num1 - num2;
     }
     console.log( add(3,5) );//8
     console.log( sub(5,3) );//2
     console.log( sub.call(add,5,3) );//把sub()的方法绑定到add()方法上。实现了sub()方法。
     console.log( sub.apply(add,[5,3]) );//2
     console.log( add.call(sub,5,3) );//8
     console.log( add.apply(sub,[5,3]) );//8

在对象中的使用：

     var person = {
         sex: "boy",
         action: function() {
             console.log( this.sex+"  good good study,day day up!" );
             //return this.sex+"  good good study,day day up!";
         }
     }
     console.log(person.action);//f() {}
    var p1 = person.action;
    p1();//undefined  good good study,day day up!
    p1.call(person);//boy good good study,day day up!
    p1.apply(person);//boy good good study,day day up!
    //使用call(),apply();被调用的对象的方法能够访问对象的属性，赋给调用者。同样可以传递参数。
    var person1 = {
         sex: "boy",
         action: function(a,b) {
             console.log( this.sex+"  good good study,day day up!"+"age: "+a+"job: "+b );
             //return this.sex+"  good good study,day day up!";
         }
     }
     console.log(person1.action);//f() {}
    var p1 = person1.action;
    p1(23,"IT");//undefined  good good study,day day up!age: 23job: IT
    p1.call(person1,23,"IT");//boy good good study,day day up!age: 23job: IT
    p1.apply(person1,[23,"IT"]);//boy good good study,day day up!age: 23job: IT

利用call()或者apply()方法可对对象等使用其他数据类型的方法；(可以理解为把谁的方法添加到调用的对象上)

    var a = {
        a: 1,
        b: "assassin",
        c: 2
    }
    //console.log(a.slice());//TypeError a.slice is not a function
    console.log( Array.prototype.slice.call(a) );//[]

可以扩展到自己的方法中：

    var animate = {
        name: "animate",
        fnAn: function() {
            console.log("animate...");
        }
    }
    var pp = {};
    animate.fnAn.call(pp);//speak...
    animate.fnAn.call(pp);//speaking

通过call和apply，我们可以实现对象继承。

    function People() {
        this.age = 23;
        this.name = "assassin";
    }
    var people = {};
    console.log( People);//ƒ People() {//...}
    console.log( people );//{}
    //People.call(people);
    People.apply(people);
    console.log(people);//{age: 23, name: "assassin"}
    //同样可以传递参数：
    function People1(age,name) {
        this.age = age;
        this.name = name;
    }
    var people1 = {};
    console.log( People1);//ƒ People(age,name) {//...}
    console.log( people1 );//{}
    //People.call(people，23,"assassin");
    People1.apply(people1,[23,"assassin"]);
    console.log(people1);//{age: 23, name: "assassin"}

bind();方法使用详解

    function fn1(a,b) {
        console.log( a*b );
    }
    function fn2(a,b) {
        console.log( a/b );
    }
    fn1(6,3);//18
    fn1.bind(fn2,6,3);//并没有执行
    fn1.bind(fn2,6,3)();//18