面向对象的javascript中成员变量的最佳方法？ [英] best approach to member variables in object-oriented javascript?

问题描述

这是我刚刚发布的问题的后续跟进。
我想知道在使用MyClass.prototype定义方法时如何处理javascript clases中的成员变量。

This is a follow up to a question I just posted. I'm wondering how you all handle member variables in javascript clases when using MyClass.prototype to define methods.

如果你定义了所有的方法构造函数：

If you define all of the methods in the constructor function:

function MyClass(){
 this.myMethod = function(){}
}

您可以很好地声明成员变量并从方法中访问它们：

You can very nicely declare member variables and access them from inside your methods:

function MyClass(){
 var myVar = "hello";
 this.myMethod = function(){
  alert(myVar);
 }
}

使用Object.prototype技术时，你会失去这个非常好，并且必须这样做;

When using the Object.prototype technique, you lose this nicety, and have to do it like this;

function MyClass(){}
MyClass.prototype.myVar = "hello";
MyClass.prototype.myMethod = function(){alert(this.hello)};

每次访问成员变量时，我都不会写this。我想使用Object.prototype方法出于内存和灵活性的原因，但在语法方面看起来很笨拙。这是你们一般的工作方式吗？

I'm not crazy about having to write "this" every time I access a member variable. I want to use the Object.prototype approach for memory and flexibility reasons, but it seems a lot clumsier syntax-wise. Is this how you folks generally work?

谢谢，

-Morgan

推荐答案

你应该克服使用这个指针访问成员变量的厌恶。

You should get over your aversion to using the this pointer to access member variables.

在构造函数中分配成员变量，您可以使用原型方法访问它们：

Assign member variables in the constructor, and you can access them with prototype methods:

function Cat(){
    this.legs = 4;
    this.temperament = 'Apathetic';
    this.sound = 'Meow';
}

Cat.prototype.speak = function(){alert(this.sound)}

var cat = new Cat();
cat.speak();

是的，这些对象属性是公开的，但正如Guido所说，我们都是成年人。毕竟，Javascript是一种纯文本，松散类型的解释语言。在这种环境中私人变量的好处充其量是不稳定的。

Yes those object attributes are public but, as Guido would say, we're all adults here. Javascript is, after all, a plain-text, loosely-typed, interpreted language. The benefits of "private" variables in this environment are shaky at best.

我说只是明确而明确地说明如何访问您的对象，违规者将自行承担风险。

I say just be explicit and obvious about how your object should be accessed, and violators will stray from that at their own risk.

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