/**
 * @param {String} className
 * @param {String/Function} superClass
 * @param {Function} classImp
 */
function $class(className, superClass, classImp){
	if(superClass === "") superClass = Object;
	var clazz = function(){
		return function(){
			if(typeof this.init == "function"){
				this.init.apply(this, arguments);
			}
		};
	}();
	var p = clazz.prototype = new superClass();
	var _super = superClass.prototype;
	window[className] = clazz;
	classImp.apply(p, [_super]);
}

/**
 * 父类 Person
 */
$class('Person','',function(){
	this.init = function(name){
		this.name = name;
	};
	this.getName = function(){
		return this.name;
	};
	this.setName = function(name){
		this.name = name;
	}
});

/**
 * 子类 Man
 */
$class('Man', Person, function(supr){
	this.init = function(name, age){
		supr.init.apply(this,[name]); // 该句很重要
		this.age = age;
	};
	this.getAge = function(){
		return this.age;
	};
	this.setAge = function(age){
		this.age = age;
	};
});
var m = new Man('Jack',25);
console.log(m.name); // Jack
console.log(m.age); // 25