JS Development Validation Form Tutorial - Validation Form (4)
In the previous section we talked about controlling the length of user names
Let’s take a look at how to control the password format and email address through js regular expressions
Even if you don’t know how to write regular expressions Expressions don’t matter. Nowadays, you can find many ready-made regular expressions for email addresses on the Internet.
Let’s take a look at the password. For example, I only need a password that is a combination of numbers and letters and should be between 6 and 10 characters.
##var rel = /^[a-zA-Z0-9]{6,10}$/ ;Let’s take a look at the regular expression of the mailboxvar reg = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+) *\.[A-Za-z0-9]+$/;We have completed the regular expression, so how to verify our form? We want to get the value of the text box, and then match it with our regular expression. If it matches, it is in compliance with the specification. If it does not match, a prompt message will be given.Here we will use test() methodThe test() method is used to retrieve whether a string matches a certain patternLet’s verify the password, which is a combination of numbers and lettersvar rel = /^[A-Za-z0-9]{6,10}$/; var val1 = document.getElementById('pwd').value;
#DOCUMENT.GetelementByid ("SP1"). Innerhtml = "Please enter the password!";
} else if (! REL.TEST (VAL1)) {
DOCUMENT.GetelementByid ("SP1"). InnerHtml = " The password does not comply with the specification! ";
}
With the above code, we have completed the verification of the password
Let’s look at the verification email address, which is actually similar to the method of verifying the password
var reg = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za- z0-9]+)*\.[A-Za-z0-9]+$/;
var val2 = document.getElementById('email').value; if(val2 == "") {
document.getElementById("sp2").innerHTML = "Please enter your email address!";
}else if(!reg.test(val2)){
document.getElementById("sp2"). innerHTML = "The email format is incorrect!";
}
With the above code, we have completed the function of verifying the email address
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！";
}
var rel = /^[A-Za-z0-9]{6,10}$/;
var val1 = document.getElementById('pwd').value;
if(val1 == ""){
document.getElementById("sp1").innerHTML = "请输入密码！";
}else if(!rel.test(val1)){
document.getElementById("sp1").innerHTML = "密码不符合规范！";
}
//验证邮箱是否为空和邮箱的格式是否正确
var reg = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/;
var val2 = document.getElementById('email').value;
if(val2 == ""){
document.getElementById("sp2").innerHTML = "请输入邮箱！";
}else if(!reg.test(val2)){
document.getElementById("sp2").innerHTML = "邮箱格式不正确！";
}
//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>
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