分享一个js中的bind方法使用

来源：http://www.cnblogs.com/yuzhongwusan/archive/2012/02/13/2348782.html
Js代码
复制代码 代码如下:

var first_object = {
num: 42
};
var second_object = {
num: 24
};
function multiply(mult) {
return this.num * mult;
}
Function.prototype.bind = function(obj) {
var method = this,
temp = function() {
return method.apply(obj, arguments);
};
return temp;
}
var first_multiply = multiply.bind(first_object);
first_multiply(5); // returns 42 * 5
var second_multiply = multiply.bind(second_object);
second_multiply(5); // returns 24 * 5