JavaScript表单验证的三种实现方式详解
作者:异步漫步时间:2026-10-29 05:24:53浏览:649
本文通过三个完整实例,详细解析了JavaScript实现表单验证的三种常见模式:传统弹窗式验证、输入框旁实时提示验证以及基于onblur事件的失焦触发验证。每种方式均涵盖邮箱格式、密码长度、一致性校验及姓名非数字限制,帮助开发者根据实际需求选择最合适的交互方案。
本文通过具体实例,详细解析了使用JavaScript进行表单验证的多种实现方案,旨在为开发者提供实用的参考代码。
传统弹窗式表单验证
第一种方案采用传统的弹窗提示方式进行验证。
具体实现代码如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>表单验证</title>
<script type="text/javascript">
function $(id) {
return document.getElementById(id);
}
function check() {
var email = $("email").value;
var password = $("password").value;
var repassword = $("repassword").value;
var name = $("name").value;
if(email == "") {
alert("Email值不能为空");
$("email").focus();
return false;
}
if(email.indexOf("@") == -1 || email.indexOf(".") == -1) {
alert("邮箱格式不正确,必须包含@和.");
$("email").focus();
return false;
}
if(password == "") {
alert("密码不能为空");
$("password").focus();
return false;
}
if(password.length < 6) {
alert("密码长度必须大于或者等于6");
$("password").focus();
return false;
}
if(repassword != password) {
alert("两次输入的密码不一致");
$("repassword").focus();
return false;
}
if(name == "") {
alert("姓名不能为空");
$("name").focus();
return false;
}
for(var i = 0; i < name.length; i++) {
var j = name.subString(i , i+1);
if(isNaN(j) == false) {
alert('姓名中不能包含数字');
$("name").focus();
return false;
}
}
}
</script>
</head>
<body>
<form name="login_form" method="post" onsubmit="return check()">
<div>
Email:<input type="text" name="email" id="email"/>
</div>
<div>
密码:<input type="password" name="password" id="password" />
</div>
<div>
重输密码:<input type="password" name="repassword" id="repassword" />
</div>
<div>
姓名:<input type="text" name="name" id="name" />
</div>
<div>
<input type="submit" value="注册" />
</div>
</form>
</body>
</html>
输入框旁提示信息的表单验证
第二种方案在输入框后方增加提示信息区域,实现更友好的交互体验。
具体实现代码如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>表单验证</title>
<script type="text/javascript">
function $(id) {
return document.getElementById(id);
}
function check() {
var email = $("email").value;
var password = $("password").value;
var repassword = $("repassword").value;
var name = $("name").value;
$("emailinfo").innerHTML = "";
$("passwordinfo").innerHTML = "";
$("repasswordinfo").innerHTML = "";
$("nameinfo").innerHTML = "";
if(email == "") {
$("emailinfo").innerHTML = "Email值不能为空";
$("email").focus();
return false;
}
if(email.indexOf("@") == -1 || email.indexOf(".") == -1) {
$("emailinfo").innerHTML = "邮箱格式不正确,必须包含@和.";
$("email").focus();
return false;
}
if(password == "") {
$("passwordinfo").innerHTML = "密码不能为空";
$("password").focus();
return false;
}
if(password.length < 6) {
$("passwordinfo").innerHTML = "密码长度必须大于或者等于6";
$("password").focus();
return false;
}
if(repassword != password) {
$("repasswordinfo").innerHTML = "两次输入的密码不一致";
$("repassword").focus();
return false;
}
if(name == "") {
$("nameinfo").innerHTML = "姓名不能为空";
$("name").focus();
return false;
}
for(var i = 0; i < name.length; i++) {
var j = name.subString(i , i+1);
if(isNaN(j) == false) {
$("nameinfo").innerHTML = '姓名中不能包含数字';
$("name").focus();
return false;
}
}
}
</script>
</head>
<body>
<form name="login_form" method="post" onsubmit="return check()">
<div>
Email:<input type="text" name="email" id="email"/><span id="emailinfo"></span>
</div>
<div>
密码:<input type="password" name="password" id="password" /><span id="passwordinfo"></span>
</div>
<div>
重输密码:<input type="password" name="repassword" id="repassword" /><span id="repasswordinfo"></span>
</div>
<div>
姓名:<input type="text" name="name" id="name" /><span id="nameinfo"></span>
</div>
<div>
<input type="submit" value="注册" />
</div>
</form>
</body>
</html>
运行效果如下图所示:

基于失焦事件的表单验证
第三种方案通过监听输入框的onblur事件,在用户离开焦点时即时触发校验函数。
具体实现代码如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>表单验证</title>
<script type="text/javascript">
function $(id) {
return document.getElementById(id);
}
function check() {
var email = $("email").value;
var password = $("password").value;
var repassword = $("repassword").value;
var name = $("name").value;
$("emailinfo").innerHTML = "";
$("passwordinfo").innerHTML = "";
$("repasswordinfo").innerHTML = "";
$("nameinfo").innerHTML = "";
if(email == "") {
$("emailinfo").innerHTML = "Email值不能为空";
return false;
}
if(email.indexOf("@") == -1 || email.indexOf(".") == -1) {
$("emailinfo").innerHTML = "邮箱格式不正确,必须包含@和.";
return false;
}
if(password == "") {
$("passwordinfo").innerHTML = "密码不能为空";
return false;
}
if(password.length < 6) {
$("passwordinfo").innerHTML = "密码长度必须大于或者等于6";
return false;
}
if(repassword != password) {
$("repasswordinfo").innerHTML = "两次输入的密码不一致";
return false;
}
if(name == "") {
$("nameinfo").innerHTML = "姓名不能为空";
return false;
}
for(var i = 0; i < name.length; i++) {
var j = name.subString(i , i+1);
if(isNaN(j) == false) {
$("nameinfo").innerHTML = '姓名中不能包含数字';
return false;
}
}
}
function checkEmail() { //校验Email
$('emailinfo').innerHTML = "";
var email = $('email').value;
if(email == "") {
$('emailinfo').innerHTML = "Email值不能为空";
return false;
}
if(email.indexOf('@') == -1 || email.indexOf('.') == -1) {
$('emailinfo').innerHTML = "Email必须包含@和.";
return false;
}
}
function checkPassword() { //校验密码
$('passwordinfo').innerHTML = "";
var password = $('password').value;
if(password == "") {
$("passwordinfo").innerHTML = "密码不能为空";
return false;
}
if(password.length < 6) {
$("passwordinfo").innerHTML = "密码长度必须大于或者等于6";
return false;
}
}
function checkRepassword() { //校验重新输入的密码
$('repassword').innerHTML = "";
var repassword = $('repassword').value;
if(repassword != password) {
$("repasswordinfo").innerHTML = "两次输入的密码不一致";
return false;
}
}
function checkName() { //校验姓名
$('nameinfo').innerHTML = "";
var name = $('name').value;
if(name == "") {
$("nameinfo").innerHTML = "姓名不能为空";
return false;
}
for(var i = 0; i < name.length; i++) {
var j = name.subString(i , i+1);
if(isNaN(j) == false) {
$("nameinfo").innerHTML = '姓名中不能包含数字';
return false;
}
}
}
</script>
</head>
<body>
<form name="login_form" method="post" onsubmit="return check()">
<div>
Email:<input type="text" name="email" id="email" onblur="checkEmail();"/><span id="emailinfo"></span>
</div>
<div>
密码:<input type="password" name="password" id="password" onblur="checkPassword();"/><span id="passwordinfo"></span>
</div>
<div>
重输密码:<input type="password" name="repassword" id="repassword" onblur="checkRepassword();"/><span id="repasswordinfo"></span>
</div>
<div>
姓名:<input type="text" name="name" id="name" onblur="checkName();"/><span id="nameinfo"></span>
</div>
<div>
<input type="submit" value="注册" />
</div>
</form>
</body>
</html>
运行效果如下图所示:

希望本文所述对大家的javascript程序设计有所帮助。
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