首页 > 代码库 > javascript 里找元素操作元素

javascript 里找元素操作元素

 

                                   javascript 

 

一、找到元素。 var d = document.getElementById("") var d = document.getElementsByName("") var d = document.getElementsByTagName("") var d = document.getElementsByClassName("")

二、操作元素。 (一)操作内容 1.表单 value 赋值,取值

2.非表单 赋值,取值 innerHTML innerText

(二)操作属性 1.获得属性值 getAttribute("属性名"),返回的是属性值。

2.给属性赋值(添加属性,修改属性) setAttribute("属性名","属性值")

3.删除属性 removeAttribute("属性名")

(三)操作样式

三、操作相关元素。

 

 

1.同意不同意代码

 

<title>无标题文档</title><script language="javascript">function keYong(){    var b = document.getElementById("btn");    b.removeAttribute("disabled");}function buKeYong(){    var b = document.getElementById("btn");    b.setAttribute("disabled","disabled");}</script></head><body><form action="" method="get"><h1>用户协议</h1><p>asdgsad</p><p>g</p><p>asdg</p><p>asdgadsgadhgadfhadfh</p><p>adfhadfhadhdafhadfhad</p><p>&nbsp;</p><p>&nbsp;</p><input name="aaa" type="radio" value="true" onclick="keYong()" />同意<input name="aaa" type="radio" value="false" onclick="buKeYong()" checked="checked" />不同意<br/><input type="Submit" value="下一步" disabled="disabled" name="btn" id="btn"/></form></body></html>


2.用户名注册表框验证

<title>无标题文档</title><style type="text/css">.eee{    color:red;}</style><script language="javascript">function docheck(){    var s = "";    var uid = document.getElementById("txtUID").value;    var p1 = document.getElementById("txtPWD1").value;    var p2 = document.getElementById("txtPWD2").value;    var email = document.getElementById("txtEmail").value;    if(uid.length==0)    {        s +=  "用户名不能为空\n";    }    if(p1.length==0)    {        s+="密码不能为空\n";    }    if(p2.length==0)    {        s+="确认密码不能为空\n";    }    if(email.length==0)    {        s+="邮箱不能为空\n";    }    if(p1 != p2)    {        s+= "两次输入的密码不一样!";    }        alert(s);}function docheck1(){    var uid = document.getElementById("txtUID").value;    var p1 = document.getElementById("txtPWD1").value;    var p2 = document.getElementById("txtPWD2").value;    var email = document.getElementById("txtEmail").value;    if(uid.length == 0)    {        document.getElementById("spUID").innerHTML = "<h1>用户名不能为空</h1>";    }    else    {        document.getElementById("spUID").innerHTML = "";    }    if(p1 != p2)    {        document.getElementById("spPWD2").innerHTML = "两次输入的密码不一样";    }    else    {        document.getElementById("");    }}</script></head><body><form ><table width="500" border="0" align="center" cellpadding="5" cellspacing="0">  <tr>    <td width=100 align="right">用户名:</td>    <td width=200>    <input type="text" name="txtUID" id="txtUID" />    </td>    <td width="200"><span id="spUID" class="eee"></span></td>  </tr>  <tr>    <td align="right">密码:</td>    <td>    <input type="text" name="txtPWD1" id="txtPWD1" />    </td>    <td><span id="spPWD1" class="eee"></span></td>  </tr>  <tr>    <td align="right">确认密码:</td>    <td>    <input type="text" name="txtPWD2" id="txtPWD2" />    </td>    <td><span id="spPWD2" class="eee"></span></td>  </tr>  <tr>    <td align="right">邮箱:</td>    <td>    <input type="text" name="txtEmail" id="txtEmail" />    </td>    <td><span id="spEmail" class="eee"></span></td>  </tr>  <tr>    <td colspan="3" align="center">    <input id="btn" type="button" value="注册(10)" disabled="disabled" onclick="docheck1()" /><br/>    <a id="a1" href="Untitled-1.html">查看用户协议</a>    </td>  </tr></table></form></body></html><script language="javascript">var n=10;function bianHua(){    n--;    if(n==0)    {        var b = document.getElementById("btn");        b.value="注册";        b.removeAttribute("disabled");    }    else    {        var b = document.getElementById("btn");        b.value="注册("+n+")";        window.setTimeout("bianHua()",1000);    }        }bianHua()/*var a = document.getElementById("a1");var s = a.getAttribute("href");alert(s);*///var b = document.getElementById("btn");//b.setAttribute("disabled","disabled");//b.removeAttribute("disabled");</script>

 

3 .点击确定出现文本框里内容


 

<title>无标题文档</title></head><body><form action="" method="get"><input name="aaa" id="txt" type="text" /><input name="aaa" id="btn" type="button" value="ClickMe" /></form><p></p><div></div><div class="aaa"></div><div id="dd"></div><div class="aaa"></div><div></div></body></html><script language="javascript">var d = document.getElementById("btn");alert(d.value);var t = document.getElementById("txt");t.value="这是一个文本框";</script>

 

javascript 里找元素操作元素