javascript每日一练（四）——DOM二

时间：2024-06-14 16:33:02

一、DOM的创建，插入，删除

　　createElement(标签名)　　appendChild(节点)　　insertBefore(节点，原有节点)　　removeChild(节点)　

 <!doctype html>
 <html>
 <head>
 <meta charset="utf-8">
 <title>创建，删除,插入元素</title>
 <script>
 window.onload = function(){
     var oUl = document.getElementById('ul1');
     var oUl2 = document.getElementById('ul2');
     var oBtn = document.getElementById('btn1');
     var oBtn2 = document.getElementById('btn2');
     var oBtn3 = document.getElementById('btn3');
     var oTxt = document.getElementById('txt1');

     oBtn.onclick = function(){
         var oLi = document.createElement('li');

         oLi.innerHTML = oTxt.value;
         oUl.appendChild(oLi);
     };

     //insertBefore    插入到...之前
     oBtn2.onclick = function(){
         var oLi = document.createElement('li');

         oLi.innerHTML = oTxt.value;

         if(oUl.children.length == 0){
             oUl.appendChild(oLi);
         }else{
             oUl.insertBefore(oLi, oUl.children[0]);
         }
     };

     oBtn3.onclick = function(){
         oUl2.removeChild(oUl2.children[0]);
     };
 };
 </script>
 </head>

 <body>
 <input id="txt1" type="text" /><button id="btn1">创建元素</button><button id="btn2">插入到第一位</button><button id="btn3">删除元素</button>
 <ul id="ul1">

 </ul>
 <hr />
 <ul id="ul2">
     <li>1</li>
     <li>2</li>
     <li>3</li>
     <li>4</li>
     <li>5</li>
 </ul>
 </body>
 </html>

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