Javascript中类和对象之间的区别 [英] Difference between a class and an object in Javascript

问题描述

有什么区别

var myView = function () {
//something goes here
};

和

var myView = function () {
//something goes here
    return {
        a: x,
        b: y
}();

我认为第一个片段创建了一个动态类，所以你可以说

I think the first snippet creates a "dynamic" class, so that you can say

var anotherView = new myView();

和第二个片段类似于单个动态对象，但我不是很确定。

and the second snippet is similar to a singleton "dynamic" object, but I'm not very sure.

推荐答案

Javascript使用原型继承，因此 本身没有类。一切都是一个对象;只是某些对象有一个共同的父对象，当名称解析查找原型链时，会找到其方法/变量。

Javascript uses prototypal inheritance, so there are no classes per se. Everything is an object; it's just that some objects have a common parent object whose methods/variables will be found when name resolution looks up the prototype chain.

你的第一个代码片段会创建一个名为<的对象code> myView 其类型是一个函数。你的第二个片段定义了一个匿名方法，它返回一个对象（有两个属性， a 和 b ），然后立即调用此方法，将结果分配给 myView 。所以在第二种情况下， myView 是一个具有两个自定义属性的对象。

Your first code snippet creates an object called myView whose type is a function. Your second snippet defines an anonymous method which returns an object (with two properties, a and b) and then immediately calls this method, assigning the result to myView. So in this second case, myView is an object with two self-defined properties.

它可能对你有所帮助阅读道格拉斯·克罗克福德关于 Javascript原型继承的描述，因为听起来你有点模糊细节。

It may help you to read Douglas Crockford's description of prototypal inheritance in Javascript, as it sounds like you're a little fuzzy on the details.

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