Cocos2d-JS中JavaScript继承

/* Simple JavaScript Inheritance
 * By John Resig http://ejohn.org/
 * MIT Licensed.
 */
// Inspired by base2 and Prototype
(function(){
  var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/;
 
  // The base Class implementation (does nothing)
  this.Class = function(){};
 
  // Create a new Class that inherits from this class
  Class.extend = function(prop) {
    var _super = this.prototype;
   
    // Instantiate a base class (but only create the instance,
    // don‘t run the init constructor)
    initializing = true;
    var prototype = new this();
    initializing = false;
   
    // Copy the properties over onto the new prototype
    for (var name in prop) {
      // Check if we‘re overwriting an existing function
      prototype[name] = typeof prop[name] == "function" &&
        typeof _super[name] == "function" && fnTest.test(prop[name]) ?
        (function(name, fn){
          return function() {
            var tmp = this._super;
           
            // Add a new ._super() method that is the same method
            // but on the super-class
            this._super = _super[name];
           
            // The method only need to be bound temporarily, so we
            // remove it when we‘re done executing
            var ret = fn.apply(this, arguments);        
            this._super = tmp;
           
            return ret;
          };
        })(name, prop[name]) :
        prop[name];
    }
   
    // The dummy class constructor
    function Class() {
      // All construction is actually done in the init method
      if ( !initializing && this.init )
        this.init.apply(this, arguments);
    }
   
    // Populate our constructed prototype object
    Class.prototype = prototype;
   
    // Enforce the constructor to be what we expect
    Class.prototype.constructor = Class;
 
    // And make this class extendable
    Class.extend = arguments.callee;
   
    return Class;
  };
})();

var Person = Class.extend({												①
    init: function (isDancing) {												②
        this.dancing = isDancing;
    },
    dance: function () {													③
        return this.dancing;
    }
});


var Ninja = Person.extend({												④
    init: function () {														⑤
        this._super(false);												⑥
    },
    dance: function () {													⑦
        // Call the inherited version of dance()
        return this._super();												⑧
    },
    swingSword: function () {												⑨
        return true;
    }
});


var p = new Person(true);												⑩
console.log(p.dance());// true												?


var n = new Ninja();														?
console.log(n.dance()); // false												?
console.log(n.swingSword()); // true	

这种简单JavaScript继承方法事实上实现了一般意义上的面向对象概念的继承和多态机制。这种简单JavaScript继承方法是Cocos2d-JS继承机制的核心，Cocos2d-JS稍微做了修改，熟悉简单JavaScript继承的用法对于理解和学习Cocos2d-JS非常的重要。

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Cocos2d-JS中JavaScript继承

原文：http://blog.csdn.net/tonny_guan/article/details/44336833