1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <title>js制作一个选项卡</title> 6 <style type="text/css"> 7 .tab_title span.active { 8 background:#000; 9 color: #FFF; 10 } 11 .tab_content { 12 border:1px solid #000; 13 padding: 20px; 14 } 15 .tab_content div { 16 display: none; 17 } 18 .tab_content div.active { 19 display: block; 20 } 21 </style> 22 23 <script type="text/javascript"> 24 //1.选取到tab选项卡 2.为选项卡添加事件 25 window.onload = function(){ 26 var arr_tab_span = document.getElementsByTagName('span'); 27 var tab_section = document.getElementById('sec_con'); 28 var arr_tab_div = tab_section.getElementsByTagName('div'); 29 30 //console.log(arr_tab_span); 31 //console.log(tab_section); 32 //console.log(arr_tab_div); 33 34 for (var i=0; i<arr_tab_span.length;i++) { 35 arr_tab_span[i].index = i; 36 arr_tab_span[i].onclick = function(){ //为选项卡点击添加事件 37 for(var j=0;j<arr_tab_span.length;j++){ 38 arr_tab_span[j].className = ''; 39 arr_tab_div[j].className = ''; 40 }//for结束 41 this.className = 'active'; 42 arr_tab_div[this.index].className = 'active'; 43 44 } 45 }//for结束 46 } 47 </script> 48 49 </head> 50 <body> 51 <div style=" 500px;"> 52 <nav class="tab_title"> 53 <span class="active">语文</span> 54 <span>数学</span> 55 <span>娱乐</span> 56 </nav> 57 <section class="tab_content" id="sec_con"> 58 <div class="active"> 59 鲁迅是语文课本上的 60 </div> 61 <div> 62 祖冲之是数学课上的 63 </div> 64 <div> 65 孙悟空是娱乐电视里的 66 </div> 67 </section> 68 </div> 69 </body> 70 </html>
代码效果如下
现在对JS代码进行改造，添加全局变量，函数不要嵌套，变成了如下，亦可用
1 <script type="text/javascript"> 2 //1.选取到tab选项卡 2.为选项卡添加事件 3 var arr_tab_span, 4 tab_section, 5 arr_tab_div; 6 window.onload = function() { 7 init(); 8 } 9 10 function init(){ 11 arr_tab_span = document.getElementsByTagName('span'); 12 tab_section = document.getElementById('sec_con'); 13 arr_tab_div = tab_section.getElementsByTagName('div'); 14 15 for(var i = 0; i < arr_tab_span.length; i++) { 16 arr_tab_span[i].index = i; 17 arr_tab_span[i].onclick = change; 18 } //for结束 19 } 20 21 function change() { //为选项卡点击添加事件 22 for(var j = 0; j < arr_tab_span.length; j++) { 23 arr_tab_span[j].className = ''; 24 arr_tab_div[j].className = ''; 25 } //for结束 26 this.className = 'active'; 27 arr_tab_div[this.index].className = 'active'; 28 } 29 30 </script>
继续改造，js代码变成如下，面向对象的方式，即可成功运行
1 <script type="text/javascript"> 2 window.onload = function() { 3 var tab1 = new Tab(); 4 tab1.init(); 5 } 6 7 function Tab(){ 8 this.arr_tab_span = document.getElementsByTagName('span'); 9 this.tab_section = document.getElementById('sec_con'); 10 this.arr_tab_div = this.tab_section.getElementsByTagName('div'); 11 } 12 13 Tab.prototype.init = function(){ 14 for(var i = 0; i < this.arr_tab_span.length; i++) { 15 var _this = this; 16 this.arr_tab_span[i].index = i; 17 //this.arr_tab_span[i].index = i; 18 this.arr_tab_span[i].onclick = function(){ 19 _this.change(this); 20 } 21 } //for结束 22 } 23 24 Tab.prototype.change = function(obj) { 25 //console.log(this); 26 //为选项卡点击添加事件 27 for(var j = 0; j < this.arr_tab_span.length; j++) { 28 this.arr_tab_span[j].className = ''; 29 this.arr_tab_div[j].className = ''; 30 } //for结束 31 obj.className = 'active'; 32 this.arr_tab_div[obj.index].className = 'active'; 33 } 34 35 </script> 36