继承模式一、

var Parent = function(name){this.name = name || 'parent';
}Parent.prototype = {obj:{a: 1},getName: function(){return this.name;}
}var Child = function(name){this.name = name || 'Child';
}Child.prototype = new Parent()var p = new Parent();var c = new Child();console.log( p.getName() )
console.log( c.getName() )

缺点：子类如果要实现父类构造器里的初始化，需要重写。

模式二、

var Parent = function(name){this.name = name || 'parent';
}Parent.prototype = {obj:{a: 1},getName: function(){return this.name;}
}var Child = function(name){Parent.apply(this, arguments);  // 改进点
}Child.prototype = new Parent()var p = new Parent();var c = new Child('child');console.log( p.getName() )
console.log( c.getName() )

缺点：父类构造函数被执行了两次，一次是在子类构造函数中，一次在赋值子类原型时，这是很多余的。

模式三、

var Parent = function(name){this.name = name || 'parent';
}Parent.prototype = {obj:{a: 1},getName: function(){return this.name;}
}var Child = function(name){Parent.apply(this, arguments);
}Child.prototype = Parent.prototype  //改进点var p = new Parent();var c = new Child('child');console.log( p.getName() )
console.log( c.getName() )

缺点：子类的修改会改变父类的值。

模式四、

var Parent = function(name){this.name = name || 'parent';
}Parent.prototype = {getName: function(){return this.name;},obj: {a:1}
}var Child = function(){Parent.apply(this, arguments);
}var F = function(){}F.prototype = Parent.prototype;Child.prototype = new F();var p = new Parent('parent');
var c = new Child('child');console.log(child.obj.a) ; //1
console.log(parent.obj.a) ; //1
child.obj.a = 2 ;
console.log(child.obj.a) ; //2
console.log(parent.obj.a) ; //2

模式五、

var deepClone = function(source,target){source = source || {} ;target = target || {};for(var i in source){if(source.hasOwnProperty(i)){if(typeof source[i] === 'object'){target[i] = (source[i] instanceof Array) ? [] : {};deepClone(source[i],target[i]) ;    }else{target[i] = source[i];}}}return target ;
} ;var extend = function(Parent,Child){Child = Child || function(){} ;    if(Parent === undefined)        return Child ;    //借用父类构造函数Child = function(){Parent.apply(this,argument) ;} ;   //通过深拷贝继承父类原型    Child.prototype = deepClone(Parent.prototype) ;    //重置constructor属性Child.prototype.constructor = Child ;
} ;