命名空间,哦,JS,我做得对吗?

除了名称空间之外,我还不清楚您要做什么,但是我在下面的分隔符下加入了一个代码评审。更多高层评论在先。

这里有几个问题。首先,你几乎 想写作吗 new function() { } . 这是一种非常先进的技术,很容易出错(而且任何维护代码的人都很容易误解)。下面有一个例子,说明了另一种不那么令人费解的方法来获得相同的效果(加上其他一些好处)。

Cat 和 Lion

var Animals = (function() {
    var publics = {};

    // A Cat
    publics.Cat = Cat;
    function Cat() {
        this.eyes = 2;
        this.legs = 4;
        this.diet = 'carnivore';
    }

    // A Lion
    publics.Lion = Lion;
    function Lion() {
        this.mane = true;
        this.origin = 'Africa';
        this.diet = 'people'; // has priority over cat's diet
    }
    Lion.prototype = new Cat();

    // Return our public symbols
    return publics;
})();

// Usage
var l = new Animals.Lion();
alert(l.eyes); // alerts "2" (inherited from Cat)
alert(l.diet); // alerts "people" (overridden by Lion)

(当然,你可以打电话 publics 你还想要什么- pubs , p this 在你身体的最外层 功能,但不那么混乱。)

但只是换个原型而已 狮子 Here's a blog post

在通过字符串查找内容方面,您可以在任何对象上使用括号表示法:

var obj = {};
obj.foo = 42;
alert(obj["foo"]); // alerts "42" by retrieving the property "foo" from `obj`
var x = "f" + "o" + "o";
alert(obj[x]);     // alerts "42" by retrieving the property "foo" from `obj`

下面是代码回顾:

// Namespace all my code
// [TJC] Use the (function() { ... })(); mechanism described above rather than
// `new function() { ... }`, which is fairly confusing to the reader and troublesome
// to use inside inner functions (see below)
var bab = new function() {

    // Declare cat object
    // [TJC] Convention is to use initial caps for constructor functions,
    // e.g. "Cat" not "cat"
    function cat()
    {
      this.eyes = 2;
      this.legs = 4;
      this.diet = 'carnivore';

      // [TJC] Don't return anything out of constructor functions
      return true;
    }

    // Declare lion object
    // [TJC] "Lion" rather than "lion" would be more conventional
    function lion()
    {
      this.mane = true;
      this.origin = 'Africa';
      this.diet = 'people'; // has priority over cat's diet

      // [TJC] Don't return anything out of constructor functions
      return true;
    }

    // Make lion a subclass of cat
    // [TJC] There are several other things you want to consider in
    // addition to replacing the prototype
    lion.prototype = new cat();

    // Create an instance of class lion
    // [TJC] From your usage below, it looks like you
    // want to be able to look up "simba" using a string
    // later. So use the below rather than this commented-out
    // line:
    //var simba = new lion();
    var instances = {};           // [TJC]
    instances.simba = new lion(); // [TJC]

    // Share diet publicly
    // [TJC] You don't need a function for this at all, just
    // expose "instances" directly. But if you want it:
    this.objInfo = function(name) {
            // [TJC] To look up something by name using a string,
            // use brackets:
        //return name; // simba works, name doesn't
            return instances[name]; // [TJC]
    };

};

alert(bab.objInfo('simba').diet);

objInfo() 在里面 bab objInfo() 简单地返回传递给它的内容。

在你的特殊情况下, objInfo("simba") 从那以后就没用了 objInfo() 只返回字符串 "simba" :

    ...
    // Share diet publicly
    this.objInfo = function(name) { // <-- If name == "simba"
        return name; // <-- This will return "simba" not the Object simba!!!
    };

};

alert(bab.objInfo('simba').diet);​ // This will check for the diet property of
                                  //   the string "simba". So it won't work.

objInfo()

请尝试以下示例:

alert(bab.objInfo('simba'));            // This will alert "simba"
alert(bab.objInfo('noodles'));          // This will alert "noodles"
alert(bab.objInfo(window).innerWidth);  // This will give you the innerWidth of

jsFiddle example of alert(bab.objInfo(window).innerWidth);

你基本上“短路”了你的整个 巴布 对象。只有 objInfo

我会这样做:

// Namespace all my code
var bab = new function() {    
    var cat = function() // Declare cat object
    {
      var protected = {}; // Protected vars & methods
      protected.eyes = 2;
      protected.legs = 4;
      protected.diet = 'carnivore';
      return protected; // Pass protected to descendants
    }
    var lion = function()
    {     
      var protected = cat();  // Make lion a subclass of cat        
      var public = {}; // Public vars & methods
      public.legs = protected.legs; // Make 1 protected var public
      public.mane = true;
      public.origin = 'Africa';
      public.diet = 'people'; // has priority over cat's diet
      return public; // Make public vars available
    }    
    var simba = lion();     // Create an instance of class lion
    simba.diet = "Asparagus"; // Change simba, but not lion
    // Get property of choice
    this.objInfo = function(property) {
        return ("Simba: " + simba[property] +
                " - Lion (this is usually private. Shown for testing.): " +
                lion()[property]);
    };
};
alert(bab.objInfo("diet"));

jsFiddle example

我在上面使用了函数继承。我发现它使用起来更简单,并且很好地利用了Javascript面向对象角色的无类特性。

lion Simba 狮子 狮子 的饮食优先于 cat 的饮食,就像你想要的。

诀窍是包装你的 protected public 返回对象中的变量和方法,并且不要忘记您还可以在您的猫科动物中创建方法。

你可以用 eval ,但我不想推荐。

您可以通过在数组中“注册”狮子来改进脚本。

// Namespace all my code
var bab = (function() {
        // Declare cat object
        function cat() {
            this.eyes = 2;
            this.legs = 4;
            this.diet = 'carnivore';

            return true;
        }

        // Declare lion object
        function lion() {
            this.mane = true;
            this.origin = 'Africa';
            this.diet = 'people'; // has priority over cat's diet

            return true;
        }

        // Make lion a subclass of cat
        lion.prototype = new cat();

        // Create an instance of class lion
//      var simba = new lion();
        var lions = {}; // Create a "lions" object to collect all of the lion instances
        lions["simba"] = new lion();

    return {
        // Share diet publicly
        objInfo: function(name) {
            return lions[name];
        };
    }
})();

alert(bab.objInfo('simba').diet);

Public and Private in JavaScript .