Javascript对象字面量，如何解决上下文？ [英] Javascript object literal, how to solve context?

问题描述

我想开始组织我的代码，所以我想使用对象字面量。在下面的情况下，我做一个伪类。我希望 init（）可以作为一个构造函数，但不幸的是，我没有看到如何根据对象上下文设置属性。

I would like to start organizing my code properly, so I want to use object literals. In the following case, I'm doing a pseudo class. I would like that init() could work as a constructor, but unfortunately, I'm not seeing how to set attributes based on object context.

    var car = {
    context : this,
    wheels : 0,
    color : '',
    speed : 0,
    init : (function(x){
        console.log(x);
        x.wheels = 4;
        x.color = 'red';
        x.speed = 120;
    })(context)
};

console.log(car.color);

推荐答案

声明对象字面量。你可以做什么：

You can't immediately run a function like that whilst declaring an object literal. What you can do:

var car = {
init : function(wheels,color,speed){
    this.wheels = wheels || 0;
    this.color = color || '';
    this.speed = speed || 0;
    return this;
  }
}.init(4,'red',120);

alert(car.speed); //=>120

这不需要：

context : this,
wheels : 0,
color : '',
speed : 0,

...并提供以下可能性：

...and offers the possibility for:

var car = {
    init : function(wheels,color,speed){
      this.wheels = wheels || 0;
      this.color = color || '';
      this.speed = speed || 0;
      return this;
     }
    },
    redAndFast = car.init(4,'red',230),
    threeWheeler = car.init(3,'yellowstriped',110);

[编辑 >是我在想？如果你想要更多的Car实例，你必须使用真实的构造函数函数，而不是对象常量：

[edit] What was I thinking? If you want more instances of Car, you'll have to use a real constructor function instead of an object literal:

var Car = function(){
  return {
    init : function(wheels,color,speed){
            this.wheels = wheels || 0;
            this.color = color || '';
            this.speed = speed || 0;
            return this;
  }
 }
},
redAndFast = new Car().init(4,'red',230),
threeWheeler = new Car().init(3,'yellowstriped',110);

可简化为：

var Car = function(wheels,color,speed){
            this.wheels = wheels || 0;
            this.color = color || '';
            this.speed = speed || 0;
    },
    redAndFast = new Car(4,'red',230),
    threeWheeler = new Car(3,'yellowstriped',110);

或者如果你想坚持某些 init like function：

Or if you wanted to cling on to some init like function:

var Car = (function(){
    function car(wheels,color,speed){
            this.wheels = wheels || 0;
            this.color = color || '';
            this.speed = speed || 0;
    }
    return {
        init: function(w,c,s){
            return new car(w,c,s);
        }
    };
 })(),
 redAndFast   = Car.init(4,'red',230),
 threeWheeler = Car.init(3,'yellowstriped',110);

< ？你可以问。好吧，事实证明，你不需要它毕竟。是不是javascript是一个美丽和灵活的语言？

But hey, what happened to my context? you may ask. Well, it turns out you didn't need it after all. Isn't javascript a beautiful and flexible language?

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