zQuery的封装有助于js初学者巩固所学知识，发散思维，有助于更好的利用js代码；
在这里你会发现其实这个选择器并不是那么难，很多基础的函数都是原先封装过的；
然后利用面向对象的方式，建立一个zQuery对象，然后把各种方法加载他的原型身上，然后再转给$；
在这里只是简单的封装了一些小方法，事件和DOM，ajax，jsonp的东西：
方法
css
attr
html
val
addClass
removeClass
show
hide
animate
index
eq
get
事件
onclick onmouseover onmouseout onmouseenter onmousemove onmouseup onmousedown onkeydown onkeyup oncontextmenu ondblclick onscroll onresize onload onerror onchange oninput onblur onfocus
DOM
$('<div></div>')
有兴趣的可以进来看看，大家一起探讨探讨！

'use strict';
function ZQuery(arg){
    this.elements=[];
    this.domString='';
    switch(typeof arg){
        case 'string':
            //元素  获取到
            if(arg.indexOf('<')!=-1){
                //存创建标签
                this.domString=arg;
            }else{
                this.elements=getEle(arg);
                this.length=this.elements.length;
            }
            break;
        case 'function':
            DOMReady(arg);
            break;
        default:
            this.elements.push(arg);
            break;
    }
}

//css================================================================================================================
ZQuery.prototype.css=function (name,value){
    if(arguments.length==2){
        for(var i=0; i<this.elements.length; i++){
            this.elements[i].style[name]=value;
        }
    }else{
        //{} 'width'
        if(typeof name=='string'){
            return getStyle(this.elements[0],name);
        }else{
            var json=name;
            for(var i=0; i<this.elements.length; i++){
                for(var name in json){
                    this.elements[i].style[name]=json[name];
                }
            }
        }
    }
    return this;
};

//attr
ZQuery.prototype.attr=function (name,value){
    if(arguments.length==2){
        for(var i=0; i<this.elements.length; i++){
            this.elements[i].setAttribute(name,value);
        }
    }else{
        //{} 'width'
        if(typeof name=='string'){
            return this.elements[0].getAttribute(name);
        }else{
            var json=name;
            for(var i=0; i<this.elements.length; i++){
                for(var name in json){
                    this.elements[i].setAttribute(name,json[name]);
                }
            }
        }
    }
    return this;
};

//html
ZQuery.prototype.html=function (str){
    if(str||str==''){
        for(var i=0; i<this.elements.length; i++){
            this.elements[i].innerHTML=str;
        }
    }else{
        return this.elements[0].innerHTML;
    }
    return this;
};

//val
ZQuery.prototype.val=function (str){
    if(str||str==''){
        for(var i=0; i<this.elements.length; i++){
            this.elements[i].value=str;
        }
    }else{
        return this.elements[0].value;
    }
    return this;
};

//addClass
ZQuery.prototype.addClass=function (sClass){
    for(var i=0; i<this.elements.length; i++){
        if(this.elements[i].className){
            var re=new RegExp('\\b'+sClass+'\\b','g');
            if(this.elements[i].className.search(re)==-1){
                this.elements[i].className+=' '+sClass;
            }
        }else{
            this.elements[i].className=sClass;
        }
        this.elements[i].className=this.elements[i].className.replace(/^\s+|\s+$/g,'').replace(/\s+/g,' ');
    }
    return this;
};

//removeClass
ZQuery.prototype.removeClass=function (sClass){
    for(var i=0; i<this.elements.length; i++){
        if(this.elements[i].className){
            var re=new RegExp('\\b'+sClass+'\\b','g');
            this.elements[i].className=this.elements[i].className.replace(re,'');
            this.elements[i].className=this.elements[i].className.replace(/^\s+|\s+$/g,'').replace(/\s+/g,' ');
            if(this.elements[i].className==''){
                this.elements[i].removeAttribute('class');
            }
        }
    }
    return this;
};

//show
ZQuery.prototype.show=function (){
    for(var i=0; i<this.elements.length; i++){
        this.elements[i].style.display='block';
    }
    return this;
};

//hide
ZQuery.prototype.hide=function (){
    for(var i=0; i<this.elements.length; i++){
        this.elements[i].style.display='none';
    }
    return this;
};

//animate
ZQuery.prototype.animate=function (json,options){
    for(var i=0; i<this.elements.length; i++){
        move(this.elements[i],json,options);
    }
    return this;
};

//eq
ZQuery.prototype.eq=function (n){
    return this.elements[n];
};

//index
ZQuery.prototype.index=function (){
    var aEle=this.elements[0].parentNode.children;
    for(var i=0; i<aEle.length; i++){
        if(aEle[i]==this.elements[0]){
            return i;
        }
    }
    return this;
};

//jq转原生
ZQuery.prototype.get=function (n){
    return this.elements[n];
};

//事件
;'click mouseover mouseout mousedown mousemove mouseup mouseenter mouseleave keydown keyup contextmenu dblclick load error scroll resize'.replace(/\w+/g,function (str){
    ZQuery.prototype[str]=function (fn){
        for(var i=0; i<this.elements.length; i++){
            addEvent(this.elements[i],str,fn);
        }
    };
    return this;
});

//hover
ZQuery.prototype.hover=function (fn1,fn2){
    this.mouseenter(fn1);
    this.mouseleave(fn2);
    return this;
};

//toggle
ZQuery.prototype.toggle=function (){
    var arg=arguments;
    var _this=this;
    for(var i=0; i<this.elements.length; i++){
        (function (count){
            _this.elements[i].onclick=function (){
                arg[count%arg.length]();
                count++;
            };
        })(0);
    }
    return this;
};

//addEvent
function addEvent(obj,sEv,fn){
    if(obj.addEventListener){
        obj.addEventListener(sEv,function (ev){
            var oEvent=ev||event;
            if(fn(oEvent)==false){
                oEvent.preventDefault();
                oEvent.cancelBubble=true;
            }
        },false);
    }else{
        obj.attachEvent('on'+sEv,function (ev){
            var oEvent=ev||event;
            if(fn(oEvent)==false){
                oEvent.cancelBubble=true;
                return false;
            }
        });
    }
    return this;
}

//DOM插入
ZQuery.prototype.appendTo=function (str){
    var aParent=getEle(str);
    for(var i=0; i<aParent.length; i++){
        //不为人知DOM操作
        aParent[i].insertAdjacentHTML('beforeEnd',this.domString);
    }
    return this;
};
ZQuery.prototype.prependTo=function (str){
    var aParent=getEle(str);
    for(var i=0; i<aParent.length; i++){
        //不为人知DOM操作
        aParent[i].insertAdjacentHTML('afterBegin',this.domString);
    }
    return this;
};
ZQuery.prototype.insertAfter=function (str){
    var aParent=getEle(str);
    for(var i=0; i<aParent.length; i++){
        //不为人知DOM操作
        aParent[i].insertAdjacentHTML('afterEnd',this.domString);
    }
    return this;
};
ZQuery.prototype.insertBefore=function (str){
    var aParent=getEle(str);
    for(var i=0; i<aParent.length; i++){
        //不为人知DOM操作
        aParent[i].insertAdjacentHTML('beforeBegin',this.domString);
    }
    return this;
};

//remove
ZQuery.prototype.remove=function (){
    for(var i=0; i<this.elements.length; i++){
        this.elements[i].parentNode.removeChild(this.elements[i]);
    }
    return this;
};

//插件
$.fn=ZQuery.prototype;
$.fn.extend=function (json){
    for(var name in json){
        ZQuery.prototype[name]=json[name];
    }
};
$.ajax=function (json){
    ajax(json);
};

$.jsonp=function (json){
    jsonp(json);
};

function jsonp(json){
    var json=json||{};
    if(!json.url)return;
    json.cbName=json.cbName||'cb';
    json.data=json.data||{};
    json.data[json.cbName]='show'+Math.random();
    json.data[json.cbName]=json.data[json.cbName].replace('.','');
    var arr=[];
    for(var name in json.data){
        arr.push(name+'='+json.data[name]);
    }
    //a=1&b=2
    var str=arr.join('&');
    window[json.data[json.cbName]]=function (result){
        json.success&&json.success(result);
        oH.removeChild(oS);
    };
    var oH=document.head;
    var oS=document.createElement('script');
    oS.src=json.url+'?'+str;
    oH.appendChild(oS);
}

//ajax
function json2url(json){
    json.t=Math.random();
    var arr=[];
    for(var name in json){
        arr.push(name+'='+json[name]);
    }
    return arr.join('&');
}
function ajax(json){
    var json=json||{};
    if(!json.url)return;
    json.data=json.data||{};
    json.type=json.type||'get';
    if(window.XMLHttpRequest){
        var oAjax=new XMLHttpRequest();
    }else{
        var oAjax=new ActiveXObject('Microsoft.XMLHTTP');
    }
    switch(json.type.toLowerCase()){
        case 'get':
            oAjax.open('GET',json.url+'?'+json2url(json.data),true);
            oAjax.send();
            break;
        case 'post':
            oAjax.open('POST',json.url,true);
            oAjax.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
            oAjax.send(json2url(json.data));
            break;
    }
    oAjax.onreadystatechange=function (){
        if(oAjax.readyState==4){
            if(oAjax.status==200){
                json.success&&json.success(oAjax.responseText); 
            }else{
                json.error&&json.error(oAjax.status);
            }
        }
    };
}

//getStyle
function getStyle(obj,sName){
    return (obj.currentStyle||getComputedStyle(obj,false))[sName];
}
//move
function move(obj,json,options){
    var options=options||{};
    options.duration=options.duration||700;
    options.easing=options.easing||'ease-out';
    var start={};
    var dis={};
    for(var name in json){
        start[name]=parseFloat(getStyle(obj,name));
        dis[name]=json[name]-start[name];
    }
    var count=Math.floor(options.duration/30);
    var n=0;
    clearInterval(obj.timer);
    obj.timer=setInterval(function (){
        n++;
        for(var name in json){
            switch(options.easing){
                case 'linear':
                    var a=n/count;
                    var cur=start[name]+dis[name]*a;
                    break;
                case 'ease-in':
                    var a=n/count;
                    var cur=start[name]+dis[name]*Math.pow(a,3);
                    break;
                case 'ease-out':
                    var a=1-n/count;
                    var cur=start[name]+dis[name]*(1-Math.pow(a,3));
                    break;
            }
            if(name=='opacity'){
                obj.style.opacity=cur;
                obj.style.filter='alpha(opacity:'+cur*100+')';
            }else{
                obj.style[name]=cur+'px';
            }
        }
        
        if(n==count){
            clearInterval(obj.timer);
        }
    },16);
}

//DOMReady
function DOMReady(fn){
    if(document.addEventListener){
        document.addEventListener('DOMContentLoaded',function (){
            fn&&fn();
        },false);
    }else{
        document.attachEvent('onreadystatechange',function (){
            if(document.readyState=='complete'){
                fn&&fn();
            }
        });
    }
}

//把new ZQuery变成$
function $(arg){
    return new ZQuery(arg);
}

//选择器
function getByClass(obj,sClass){
    if(obj.getElementsByClassName){
        return obj.getElementsByClassName(sClass);
    }
    var aResult=[];
    var aEle=obj.getElementsByTagName('*');
    var re=new RegExp('\\b'+sClass+'\\b','g');
    for(var i=0; i<aEle.length; i++){
        if(aEle[i].className.search(re)!=-1){
            aResult.push(aEle[i]);
        }
    }
    return aResult;
}

function getByStr(aParent,str){
    var aChild=[];
    for(var i=0; i<aParent.length; i++){
        switch(str.charAt(0)){
            case '#':
                var obj=document.getElementById(str.substring(1));
                aChild.push(obj);
                break;
            case '.':
                var aEle=getByClass(aParent[i],str.substring(1));
                for(var j=0; j<aEle.length; j++){
                    aChild.push(aEle[j]);
                }
                break;
            default:
                if(/^\w+\.\w+$/.test(str)){
                //li.on
                    var arr=str.split('.');
                    var aEle=aParent[i].getElementsByTagName(arr[0]);
                    var re=new RegExp('\\b'+arr[1]+'\\b','g');
                    for(var j=0; j<aEle.length; j++){
                        if(aEle[j].className.search(re)!=-1){
                            aChild.push(aEle[j]);
                        }
                    }
                }else if(/^\w+\[\w+\=\w+\]$/.test(str)){
                    //input[type=text]
                    var arr=str.split(/\[|\=|\]/g);
                    var aEle=aParent[i].getElementsByTagName(arr[0]);
                    for(var j=0; j<aEle.length; j++){
                        if(aEle[j].getAttribute(arr[1])==arr[2]){
                            aChild.push(aEle[j]);
                        }
                    }
                }else if(/^\w+\:\w+(\(\d+\))?$/.test(str)){
                    //li:first li:eq(0)
                    var arr=str.split(/\:|\(|\)/g);
                    var aEle=aParent[i].getElementsByTagName(arr[0]);
                    switch(arr[1]){
                        case 'first':
                            aChild.push(aEle[0]);
                            break;
                        case 'last':
                            aChild.push(aEle[aEle.length-1]);
                            break;
                        case 'even':
                            for(var j=0; j<aEle.length; j+=2){
                                aChild.push(aEle[j]);
                            }
                            break;
                        case 'odd':
                            for(var j=1; j<aEle.length; j+=2){
                                aChild.push(aEle[j]);
                            }
                            break;
                        case 'eq':
                            aChild.push(aEle[arr[2]]);
                            break;
                        case 'lt':
                            for(var j=0; j<arr[2]; j++){
                                aChild.push(aEle[j]);
                            }
                            break;
                        case 'gt':
                            for(var j=arr[2]; j<aEle.length; j++){
                                aChild.push(aEle[j]);
                            }
                            break;
                    }
                }else{
                    var aEle=aParent[i].getElementsByTagName(str);
                    for(var j=0; j<aEle.length; j++){
                        aChild.push(aEle[j]);
                    }
                }
                break;
        }
    }
    return aChild;
}

function getEle(str){
    var arr=str.replace(/^\s+|\s+$/g,'').split(/\s+/g);
    var aChild=[];
    var aParent=[document];
    
    for(var i=0; i<arr.length; i++){
        aChild=getByStr(aParent,arr[i]);
        aParent=aChild;
    }
    
    return aChild;
}