使用JavaScript对象文字表示法的JavaScript构造函数 [英] JavaScript constructors using JavaScript object literal notation

问题描述

使用对象文字符号在JavaScript中构建构造函数的最佳方法是什么?

What is the best way to build constructors in JavaScript using object literal notation?

var myObject = {
 funca : function() {
  //...
 },

 funcb : function() {
  //...
 }
};

我希望能够打电话

var myVar = new myObject(...);

并将参数传递给myObject内的构造函数.

And pass the arguments to a constructor function inside myObject.

推荐答案

这不是不是"JSON表示法"，这是JavaScript 对象文字表示法. JSON只是JS对象文字表示法的一个子集，但是除了看起来相似之外，它们没有任何共同点. JSON被用作数据交换格式，例如XML.

This is not "JSON notation", this is JavaScript object literal notation. JSON is only a subset of JS object literal notation, but apart from looking similar, they have nothing in common. JSON is used as data exchange format, like XML.

不可能做.

var myObject = {};

已经创建了一个对象.没有什么可以实例化的.

creates already an object. There is nothing what you can instantiate.

不过，您可以创建一个构造函数并将方法添加到其原型中:

You can however create a constructor function and add the methods to its prototype:

function MyObject(arg1, arg2) {
    // this refers to the new instance
    this.arg1 = arg1;
    this.arg2 = arg2;

    // you can also call methods
    this.funca(arg1);
}

MyObject.prototype = {
 funca : function() {
  // can access `this.arg1`, `this.arg2`
 },

 funcb : function() {
  // can access `this.arg1`, `this.arg2`
 }
};

您用new MyObject()实例化的每个对象都将继承原型的属性(实际上，实例只是获得对原型对象的引用).

Every object you instantiate with new MyObject() will inherit the properties of the prototype (actually, the instances just get a reference to the prototype object).

有关JavaScript对象和继承的更多信息:

More about JavaScript objects and inheritance:

• 使用对象
• 对象模型的详细信息
• 重访继承

• Working with objects
• Details of the object model
• Inheritance revisited

Update2:

如果必须实例化许多相同种类的对象，请使用构造函数+原型.如果您只需要一个对象(如单例)，则无需使用构造函数(大部分时间).您可以直接使用对象文字表示法创建该对象.

If you have to instantiate many objects of the same kind, then use a constructor function + prototype. If you only need one object (like a singleton) then there is no need to use a constructor function (most of the time). You can directly use object literal notation to create that object.

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