1.学习资料
【优极限】 HTML+CSS+JavaScript+jQuery前端必学教程,小白教学,前端基础全套完成版_哔哩哔哩_bilibili
2.表单的获取以及下拉框
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<form id="myform1" name="myform1" action=""></form>
<form id="myform2" name="myform2" action=""></form>
<form id="myform" name="myform" action="" method="get">
姓名:<input type="text" id="uname" name="uname" value="zhangsan" />
<br />
密码:<input type="password" id="upwd" name="upwd" value="1234"/>
<br />
<input type="hidden" id="uno" name="uno" value="隐藏域" />
<br />
个人说明:<textarea name="utron"></textarea>
<br />
<button type="button" onclick="getTX();">获取元素内容</button>
</form>
<script type="text/javascript">
console.log(document.getElementById("myform1"));//id属性
console.log(document.myform2);//name属性
console.log("-----------")
console.log(document.forms);
console.log(document.forms[1]);
console.log(document.forms['myform2']);
console.log("-----------")
function getTX(){
var name=document.getElementById("uname").value;
console.log(name);
var upwd=document.getElementById("myform").upwd.value;
console.log(upwd);
var uno=document.getElementsByName("uno")[0].value;
console.log(uno);
var utron=document.getElementsByTagName("textarea")[0].value;
console.log(utron);
}
</script>
</body>
</html>
2.1 获取表单,单选按钮
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<select id="uform" name="uform">
<option value="">请选择</option>
<option value="beijing" selected="selected">北京</option>
<option value="shanghai">上海</option>
<option>杭州</option>
</select>
<button type="button" onclick="gethh()">获取下拉选项</button>
<script type="text/javascript">
function gethh(){
var uform=document.getElementById("uform");//获取下拉框对象
console.log(uform);
var opts=uform.options;//获取下拉框的下拉选项列表
console.log(opts);
var index=uform.selectedIndex;//获取下拉框被选中项的索引
console.log("选中项的下标:"+index);
var val=uform.value;//获取下拉框被选中项的值
console.log("被选中项的值:"+val);
var val2=uform.options[index].value;//通过选中项的下标获取下拉框被选中的值
console.log("被选中的值:"+val2);
var txt=uform.options[index].text;//获取下拉框被选中的文本项
console.log("被选中的文本:"+txt);
//设置上海被选中的项
uform.options[2].selected=true;
}
</script>
</body>
</html>
2.2 提交按钮(submit一定要设置返回值当为false是阻止事件发生)
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<form id="my" action="https://www.baidu.com/?tn=62095104_34_oem_dg" method="get">
姓名<input name="uname" id="uname"/> <span id="msg" style="font-size: 12px; color: #00FFFF;"></span> <br/>
<button type="button" onclick="getl()">提交</button>
</form>
<form id="my2" action="https://www.baidu.com/?tn=62095104_34_oem_dg" method="get">
姓名<input name="uname2" id="uname2"/> <span id="msg2" style="font-size: 12px; color: #00FFFF;"></span> <br/>
<button type="submit" onclick="return get2()">提交</button>
</form>
<script type="text/javascript">
function getl(){
var name=document.getElementById("uname").value;
if(empty(name)){
document.getElementById("msg").innerHTML="姓名不能为空!"
return;
}
document.getElementById("my").submit();
}
function empty(str){
if(str==null||str.trim()==""){
return true;
}
return false
}
function get2(){
var name1=document.getElementById("uname2").value;
if(empty(name1)){
document.getElementById("msg2").innerHTML="姓名不能为空!"
return false;
}
return true;
}
</script>
</body>
</html>
当有信息时,会进行页面的跳转,因为我的action是百度