js借用和绑定

var one = {
    name:"object",
    say:function(greet) {
        return greet + ","+this.name;
    }
}
//console.log(one.say("hi"));  //结果hi,object
var two = {
    name:"another"
};
console.log(one.say.apply(two,["hello"]));  //结果hello,another

//给变量赋值，“this”将会指向全局变量
var say = one.say;
console.log(say("you")); //结果you,undefined

//作为回调函数使用
var yetanother = {
    name:"yet",
    method:function(callback){
        return callback("HOHO");
    }
}
console.log(yetanother.method(one.say));//结果HOHO,undefined

function bind(o,m){
    return function(){
        return m.apply(o,[].slice.call(arguments));
    }
}

var twoSay = bind(two,one.say);
console.log(twoSay("jie"));  //jie,another