JavaScript节点的常用属性和方法
节点就是标签对象
<div class="inner"> <div class="divleft"> <p>你最喜欢哪个城市?</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> 你最喜欢哪款游戏？ </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="inner1"> 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"> </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">查找#city下所有子节点</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>
innerHTML 获取起始标签到结束标签中的内容
document.getElementById("btn01").onclick = function (){
var bjObj = document.getElementById("bj");
alert(bjObj.innerHTML); //innerHTML是获取标签头到标签尾的内容
}
查找一个标签下的子标签
document.getElementById("btn04").onclick = function (){
var liObjs02 = document.getElementById("city").getElementsByTagName("li");//将city下的li节点通过查找标签名查找出来
alert(liObjs02.length);
}
childNodes 查找标签下的所有子节点
在childNodes解析时会把空格也解析成节点
document.getElementById("btn05").onclick = function(){
var citychildObjs = document.getElementById("city").childNodes;
alert(citychildObjs.length);
}
firstChlid取当前节点的第一个子节点
注意 在子标签前面的空格也会被作为节点，也就是说，如说标签前有空格 就会查找到那个空格而不是我们想要查找的那个标签
document.getElementById("btn06").onclick = function (){
var phonefirstchild = document.getElementById("phone").firstChild;
alert(phonefirstchild.innerHTML);
<ul id="phone"><li>IOS</li> <li id="android">Android</li> <li>Windows Phone</li> </ul>
<ul id="phone"> <li>IOS</li> <li id="android">Android</li> <li>Windows Phone</li>
parentNode获取当前节点的父节点
document.getElementById("btn07").onclick = function (){
var bjparentObj = document.getElementById("bj").parentNode;
alert(bjparentObj);
}
previouSibling获取当前节点前面的节点
document.getElementById("btn08").onclick = function (){
var androidObj = document.getElementById("android").previousSibling;
alert(androidObj.innerHTML);
}
innertext只取文本内容不取标签
<head> <meta charset="UTF-8"> <title>查找</title> <style type="text/css"> .inner{ width: 600px; height: 370px; border-style: solid; margin-left: 200px; float: left; } .inner1{ width: 600px; height: 100px; border-style: solid; margin-top: 50px; } #btnList{ margin-top: 20px; float: left; margin-left: 100px; } button{ width: 300px; height: 30px; margin: 5px; } ul li{ width: 100px; height: 50px; background-color: #9ad99a; border-style: solid; list-style-type: none; display: inline; font-size: 20px; } </style> <script type="text/javascript"> window.onload = function (){ document.getElementById("btn01").onclick = function (){ var bjObj = document.getElementById("bj"); alert(bjObj.innerHTML); //innerHTML是获取标签头到标签尾的内容 } document.getElementById("btn02").onclick = function (){ var liObjjs = document.getElementsByTagName("li"); alert(liObjjs.length) } document.getElementById("btn03").onclick = function (){ var genderObj = document.getElementsByName("gender"); alert(genderObj.length); } document.getElementById("btn04").onclick = function (){ var liObjs02 = document.getElementById("city").getElementsByTagName("li");//将city下的li节点通过查找标签名查找出来 alert(liObjs02.length); } document.getElementById("btn05").onclick = function(){ var citychildObjs = document.getElementById("city").childNodes; alert(citychildObjs.length); } document.getElementById("btn06").onclick = function (){ var phonefirstchild = document.getElementById("phone").firstChild; alert(phonefirstchild.innerHTML); } document.getElementById("btn07").onclick = function (){ var bjparentObj = document.getElementById("bj").parentNode; alert(bjparentObj); } document.getElementById("btn08").onclick = function (){ var androidObj = document.getElementById("android").previousSibling; alert(androidObj.innerHTML); } document.getElementById("btn09").onclick = function (){ var nametext = document.getElementById("username").value; alert(nametext); } document.getElementById("btn10").onclick = function (){ document.getElementById("username").value = "魏子涵"; } document.getElementById("btn11").onclick = function (){ alert(document.getElementById("bj").innerHTML); } } </script> </head> <body> <div class="inner"> <div class="divleft"> <p>你最喜欢哪个城市?</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> 你最喜欢哪款游戏？ </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="inner1"> 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"> </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">查找#city下所有子节点</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>
