js进行表单验证实例分析

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我是靠谱客的博主糊涂春天，最近开发中收集的这篇文章主要介绍js进行表单验证实例分析，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

本文实例讲述了js进行表单验证的方法。分享给大家供大家参考。具体实现方法如下：

1. 传统的表单验证代码

复制代码代码如下:

<!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>

2. 输入框后面有提示信息的表单验证

复制代码代码如下:

<!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>

效果图如下所示：

3. 在输入框失去焦点时触发校验函数

复制代码代码如下:

<!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>