<!doctype html> <html> <head> <meta charset="utf-8"> <title>全局类名获取</title> <meta name="keywords" content=""> <meta name="description" content=""> <style> *{margin:0; padding:0; list-style:none;} .bgred{ background: red; } .blue{ color: blue; } </style> </head> <body> <ul> <li class="bgred">111</li> <li class="bgred blue">222</li> <li class="bgred">333</li> <li class="bgred">111</li> <li class="bgred blue">222</li> <li class="bgred">333</li> </ul> <script> function byClass1(oClass){//全局获取 var tags=document.all?document.all:document.getElementsByTagName('*'); var arr=[]; for (var i = 0; i < tags.length; i++) { var classNa=tags[i].className; var num=classNa.indexOf(oClass,0); if (num!=-1) { arr.push(tags[i]); }; }; return arr; } var liRed=byClass1('bgred'); alert(liRed.length);//6 </script> </body> </html>
通过标签名和ID名我们可以很容易的获得想要操作的标签，但通过类名获取大家有没有想过呢，上面的代码可以实现从全局中通过类名获取标签进行操作；