javascript替换已有元素replaceChild()使用介绍

var oDiv = document.getElementById("guoDiv"); 
var oSpan = document.createElement("span"); 
oSpan.innerHTML = "4"; 
var firsChild = oDiv.firstElementChild ? oDiv.firstElementChild : oDiv.firstChild 
var returnNode = oDiv.replaceChild(oSpan, firsChild); //替换第一个元素,返回被替换掉的元素 
alert(returnNode.innerHTML); //1 
var lastChild = oDiv.lastElementChild ? oDiv.lastElementChild : oDiv.lastChild; 
oSpan = document.createElement("span"); 
oSpan.innerHTML = "5"; 
returnNode = oDiv.replaceChild(oSpan, lastChild); //替换最后一个,返回被替换掉的元素 
alert(returnNode.innerHTML);//3 
 
 代码如下:

<div id="guoDiv"> 
<span>1</span> 
<span>2</span> 
<span>3</span> 
</div>