节点就是标签对象
DOM 查询练习
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>dom查询</title>
<link rel="stylesheet" type="text/css" href="style/css.css" />
<script type="text/javascript">
window.onload = function(){
//1.查找#bj节点
document.getElementById("btn01").onclick = function () {
var bjObj = document.getElementById("bj");
alert(bjObj.innerHTML);
}
//2.查找所有li节点
var btn02Ele = document.getElementById("btn02");
btn02Ele.onclick = function(){
var lis = document.getElementsByTagName("li");
alert(lis.length)
};
//3.查找name=gender的所有节点
var btn03Ele = document.getElementById("btn03");
btn03Ele.onclick = function(){
var genders = document.getElementsByName("gender");
alert(genders.length)
};
//4.查找#city下所有li节点
var btn04Ele = document.getElementById("btn04");
btn04Ele.onclick = function(){
//1 获取id为city的节点
//2 通过city节点.getElementsByTagName按标签名查子节点
var lis = document.getElementById("city").getElementsByTagName("li");
alert(lis.length)
};
//5.返回#city的所有子节点
var btn05Ele = document.getElementById("btn05");
btn05Ele.onclick = function(){
//1 获取id为city的节点
//2 通过city获取所有子节点
alert(document.getElementById("city").childNodes.length);
};
//6.返回#phone的第一个子节点
var btn06Ele = document.getElementById("btn06");
btn06Ele.onclick = function(){
// 查询id为phone的节点
alert( document.getElementById("phone").firstChild.innerHTML );
};
//7.返回#bj的父节点
var btn07Ele = document.getElementById("btn07");
btn07Ele.onclick = function(){
//1 查询id为bj的节点
var bjObj = document.getElementById("bj");
//2 bj节点获取父节点
alert( bjObj.parentNode.innerHTML );
};
//8.返回#android的前一个兄弟节点
var btn08Ele = document.getElementById("btn08");
btn08Ele.onclick = function(){
// 获取id为android的节点
// 通过android节点获取前面兄弟节点
alert( document.getElementById("android").previousSibling.innerHTML );
};
//9.读取#username的value属性值
var btn09Ele = document.getElementById("btn09");
btn09Ele.onclick = function(){
alert(document.getElementById("username").value);
};
//10.设置#username的value属性值
var btn10Ele = document.getElementById("btn10");
btn10Ele.onclick = function(){
document.getElementById("username").value = "国哥你真牛逼";
};
//11.返回#bj的文本值
var btn11Ele = document.getElementById("btn11");
btn11Ele.onclick = function(){
alert(document.getElementById("city").innerHTML);
// alert(document.getElementById("city").innerText);
};
};
</script>
</head>
<body>
<div id="total">
<div class="inner">
<p>
你喜欢哪个城市?
</p>
<ul id="city">
<li id="bj">北京</li>
<li>上海</li>
<li>东京</li>
<li>首尔</li>
</ul>
<br>
<br>
<p>
你喜欢哪款单机游戏?
</p>
<ul id="game">
<li id="rl">红警</li>
<li>实况</li>
<li>极品飞车</li>
<li>魔兽</li>
</ul>
<br />
<br />
<p>
你手机的操作系统是?
</p>
<ul id="phone"><li>IOS</li><li id="android">Android</li><li>Windows Phone</li></ul>
</div>
<div class="inner">
gender:
<input type="radio" name="gender" value="male"/>
Male
<input type="radio" name="gender" value="female"/>
Female
<br>
<br>
name:
<input type="text" name="name" id="username" value="abcde"/>
</div>
</div>
<div id="btnList">
<div><button id="btn01">查找#bj节点</button></div>
<div><button id="btn02">查找所有li节点</button></div>
<div><button id="btn03">查找name=gender的所有节点</button></div>
<div><button id="btn04">查找#city下所有li节点</button></div>
<div><button id="btn05">返回#city的所有子节点</button></div>
<div><button id="btn06">返回#phone的第一个子节点</button></div>
<div><button id="btn07">返回#bj的父节点</button></div>
<div><button id="btn08">返回#android的前一个兄弟节点</button></div>
<div><button id="btn09">返回#username的value属性值</button></div>
<div><button id="btn10">设置#username的value属性值</button></div>
<div><button id="btn11">返回#bj的文本值</button></div>
</div>
</body>
</html>
css文件：
@CHARSET "UTF-8";
body {
width: 800px;
margin-left: auto;
margin-right: auto;
}
button {
width: 300px;
margin-bottom: 10px;
}
#btnList {
float:left;
}
#total{
width: 450px;
float:left;
}
ul{
list-style-type: none;
margin: 0px;
padding: 0px;
}
.inner li{
border-style: solid;
border-width: 1px;
padding: 5px;
margin: 5px;
background-color: #99ff99;
float:left;
}
.inner{
width:400px;
border-style: solid;
border-width: 1px;
margin-bottom: 10px;
padding: 10px;
float: left;
}
