(1) Key summary of javascript in Silicon Valley (6) [Common attributes and methods of nodes] [DOM query exercise]

 
 

Node is label object

 
 
 

DOM query exercise

 
<!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 file:

@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;
}

 

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Origin blog.csdn.net/qq_41048982/article/details/108971350