javascript设计模式5

子类引用父类

function extend(subClass,superClass){
    var F=function(){};
    F.prototype=superClass.prototype;
    subClass.prototype=new F();
    subClass.prototype.constructor=subClass;
    subClass.superClass=superClass.prototype;
    if(subClass.prototype.constructor==Object.prototype.constructor){
        superClass.prototype.constructor=superClass;
    }
}

原型式继承

var Person={
    name:'default name',
    getName:function(){
        return this.name;
    }
};

用工厂模式

var CompoundObject={};
CompoundObject.string1='default value',
CompoundObject.createChildObject=function(){
    return{
        bool:true,
        num:10
    }
};
CompoundObject.childObject=CompoundObject.createChildObject();
var compoundObjectClone=clone(CompoundObject);
compoundObjectClone.childObject=CompoundObject.createChildObject();
compoundObjectClone.childObject.num=5;

例子中的clone函数

function clone(object){
    function F(){}
    F.prototype=object;
    return new F;
}

掺元类：通过扩充的方式共享函数

var Mixin=function(){};
Mixin.prototype={
    serialize:function(){
        var output=[];
        for(key in this){
            output.push(key+':'+this[key]);
        }
        return output.join(',');
    }
}

function augment(receivingClass,givingClass){
    if(arguments[2]){
        for(var i=2,len=arguments.length;i<len;i++){
            receivingClass.prototype[arguments[i]]=givingClass.prototype[arguments[i]];
        }
    }
    else{
        for(methodName in givingClass.prototype){
            if(!receivingClass.prototype[methodName]){
                receivingClass.prototype[methodName]=givingClass.prototype[methodName];
            }
        }
    }
}