[RuBrain]

Прошу прощения, мой косяк, чуть ниже было описание функции. Вот весь код:

function enumeration(namesToValues) {
    // This is the dummy constructor function that will be the return value.
    var enumeration = function() { throw "Can't Instantiate Enumerations"; };

    // Enumerated values inherit from this object.
    var proto = enumeration.prototype = {
        constructor: enumeration,                   // Identify type
        toString: function() { return this.name; }, // Return name
        valueOf: function() { return this.value; }, // Return value
        toJSON: function() { return this.name; }    // For serialization
    };

    enumeration.values = [];  // An array of the enumerated value objects

    // Now create the instances of this new type.
    for(name in namesToValues) {         // For each value 
        var e = Object.create(proto);          // Create an object to represent it
        e.name = name;                   // Give it a name
        e.value = namesToValues[name];   // And a value
        enumeration[name] = e;           // Make it a property of constructor
        enumeration.values.push(e);      // And store in the values array
    }
    // A class method for iterating the instances of the class
    enumeration.foreach = function(f,c) {
        for(var i = 0; i < this.values.length; i++) f.call(c,this.values[i]);
    };

    // Return the constructor that identifies the new type
    return enumeration;
}


// Create a new Coin class with four values: Coin.Penny, Coin.Nickel, etc.
var Coin = enumeration({Penny: 1, Nickel:5, Dime:10, Quarter:25});
var c = Coin.Dime; // This is an instance of the new class

Скажите, как часто на практике вообще применяется подобное?