<div class="box" id="box"> <ul class="list">  <li class="in_active">第一張選項卡</li>  <li class="in">第二張選項卡</li>  <li class="in">第三張選項卡</li> </ul> <nav class="conList">  <a class="con_active" href="javascript:;">第一個控制按鈕</a>  <a class="con" href="javascript:;">第二個控制按鈕</a>  <a class="con" href="javascript:;">第三個控制按鈕</a> </nav> </div>

/*in為選項卡普通狀態，默認不顯示*/.in,.in_active{ display: none; width: 600px; height: 100px; background: orange; font-size: 50px; line-height: 100px; text-align: center;}/*in_active為選項卡選中狀態，選中后顯示*/.in_active{ display: block;}/*con為按鈕普通狀態，默認文字顏色為黑色*/.con,.con_active{ color: black; background-color: orange;}/*con_active為按鈕選中狀態，選中后文字顏色為白色*/.con_active{ color: white; }

function Tab(obj){ /*元素獲取*/ //獲取選項卡展示部分 this.oList = obj.getElementsByTagName('ul')[0]; this.aIn = this.oList.getElementsByTagName('li'); //獲取選項卡控制部分 this.oConList = obj.getElementsByTagName('nav')[0]; this.aCon = this.oConList.getElementsByTagName('a'); /*變量設置*/ //選項卡張數 this.count = this.aIn.length; //當前第幾張 this.cur = 0; var _this = this; for(var i = 0; i < this.count; i++){  //設置索引  this.aCon[i].index = i;  //給按鈕添加事件  this.aCon[i].onclick = function(){   _this.cur = this.index;   _this.switch();  } }}Tab.prototype.switch = function(){ //去掉所有 for(var i = 0; i < this.count; i++){  this.aIn[i].className = 'in';  this.aCon[i].className = 'con'; } //顯示當前 this.aIn[this.cur].className = 'in_active'; this.aCon[this.cur].className = 'con_active'; }//獲取選項卡元素var oBox = document.getElementById('box');//構造選項卡對象var tab1 = new Tab(oBox);