bind方法和bindAll方法都是用来设定函数的this值的,区别是调用方式不同。
var xiaoming = { say:function(){ console.log('I am xiaoming'); } } //bind var func = bind(xiaoming, xiaoming.say); func(); // I am xiaoming //bindAll bindAll(xiaoming, 'say'); var func = xiaoming.say; func(); // I am xiaoming
bind和bindAll都是改变函数的this指向,然后返回一个新的函数,永久的指向这个this指向
举例
function Person(name,age){ this.name = name; this.age = age; bindAll(this, 'sayName', 'sayAge'); } Person.prototype.sayName = function(){ console.log(this.name); } Person.prototype.sayAge = function(){ console.log(this.age); } var person = new Person('xiaoming',26); var func = person.sayName; func(); $('button').click(person.sayAge);
无论如何调用,sayName和sayPerson的this都指向person对象。