Let’s look at the following, verify the user name
We said before that the verification of the user name cannot be empty
Let’s verify the length of the user name and give a length value In the length value, for the correct, exceeding length or less than the length, it is illegal user name
， Let's write code:
// Verify whether the user name is empty. If为空，给出提示信息
var val = document.getElementById('name').value;
var rel = document.getElementById('name').value.length;
if(val = = "") {
document.GetelementByid ("sp"). Innerhtml = "Username cannot be empty!"; # document.getElementById("sp").innerHTML = "The format is incorrect!";
}
First we get the length and judge the length. If it is less than or equal to 5 or greater than 10, it Tip
The complete code is as follows:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
*{margin:0;padding:0;}
#div{width:410px;height:400px;background:#46a3ff;padding-left:16px;
padding-top:20px;}
input{
outline:none;
box-sizing:border-box;padding-left:15px;}
textarea{
outline:none;resize : none;
box-sizing:border-box;padding-left:15px;padding-top:5px;}
.name{width:200px;height:30px;margin-left:8px;border:1px solid #ffc1e0;border-radius:8px;}
.pwd{width:200px;height:30px;
margin-left:8px;border:1px solid #ffc1e0;border-radius:8px;}
.email{width:200px;height:30px;margin-left:8px;border:1px solid #ffc1e0;border-radius:8px;}
.txt{
width:280px;height:70px;margin-left:8px;border:1px solid #ffc1e0;border-radius:8px;}
.sub{width:100px;height:30px;padding-left:0px;
border:none;
border-radius:5px;background:#ffd0ff;}
.sub:hover{background:#ffaad5;}
.div{
width:200px;height:30px;margin:0 auto;box-sizing:border-box;padding-left:45px;padding-top:5px;color:#8600ff;font-weight:bold;}
</style>
</head>
<body>
<div id="div">
<form>
<label>用户名:</label>
<input type="text" class="name" id="name">
<div id="sp" class="div"></div>
<label>密 码:</label>
<input type="password" class="pwd" id="pwd">
<div id="sp1" class="div"></div>
<label>邮 箱:</label>
<input type="text" class="email" id="email">
<div id="sp2" class="div"></div>
<label>爱 好:</label>
<textarea rows="5" cols="40" class="txt" id="txt"></textarea>
<div id="sp3" class="div"></div>
<input type="button" class="sub" value="注册" id="sub">
</form>
</div>
<script type="text/javascript">
var sub = document.getElementById('sub');
sub.onclick=function(){
//验证用户名是否为空,如果为空，给出提示信息
var val = document.getElementById('name').value;
var rel = document.getElementById('name').value.length;
//console.log(val.length);
if(val == ""){
document.getElementById("sp").innerHTML = "用户名不能为空！";
}else if( rel <= 5 || rel > 10){
document.getElementById("sp").innerHTML = "格式不正确！";
}
//验证密码是否为空，为空则给出提示信息
var rel = /^[A-Za-z0-9]{6,10}$/;
var val1 = document.getElementById('pwd').value;
if(val1 == ""){
document.getElementById("sp1").innerHTML = "请输入密码！";
}
//验证邮箱是否为空和邮箱的格式是否正确
var val2 = document.getElementById('email').value;
if(val2 == ""){
document.getElementById("sp2").innerHTML = "请输入邮箱！";
}
//验证内容是否为空
var val3 = document.getElementById('txt').value;
if(val3 == ""){
document.getElementById("sp3").innerHTML = "请输入内容！";
}
}
//当用户名的文本框触发键盘事件，提示信息去除
document.getElementById('name').onkeyup=function(){
document.getElementById('sp').innerHTML = " ";
}
// //当密码框触发键盘事件，提示信息去除
document.getElementById('pwd').onkeyup=function(){
document.getElementById('sp1').innerHTML = " ";
}
// //当邮箱文本框触发键盘事件，提示信息去除
document.getElementById('email').onkeyup=function(){
document.getElementById('sp2').innerHTML = " ";
}
// //当文本域触发键盘事件，提示信息去除
document.getElementById('txt').onkeyup=function(){
document.getElementById('sp3').innerHTML = " ";
}
</script>
</body>
</html>In this way, our verification of the user name is completed
