JavaScript之bind,call,apply

参考：

• http://rangercyh.blog.51cto.com/1444712/1615809

function foo(a,b) {
    this.x = this.x + a + b;
}
//case 1:
var obj = {x:3};
foo.apply(obj,[1,2]);
//obj <==> {x:6}

//case 2:
var obj = {x:3};
foo.call(obj, 1, 2);
//obj <==> {x:6}

//case 3:
var obj = {x:3};
var foo1 = foo.bind(obj, 1, 2);
foo1();
//obj <==> {x:6}

区别：

call与apply的区别在于apply中传给foo的参数统一放到第二个参数数组中，call从第二个参数起皆为传给foo的参数；

call与bind的区别，call将立刻执行，bind返回一个新函数；