使用jquery.validate.js，它有微软ajax CDN。

$('#form').validate({
    rules:{
        "name":{
            required:true,
            maxlength:40
        },

        "email":{
            required:true,
            email:true, //for validate email
            maxlength:100
        },

        "message":{
            required:true
        }
    }
});

你可以使用jQuery验证，在单个HTML行中，你可以验证电子邮件和电子邮件验证消息:type="email" required data-msg-email="输入一个有效的电子邮件帐户!"

您可以使用data-msg-email参数来放置个性化的消息，否则不放置此参数，将显示默认消息:“请输入有效的电子邮件地址。”

完整的例子:

<form class="cmxform" id="commentForm" method="get" action="">
  <fieldset>
    <p>
      <label for="cemail">E-Mail (required)</label>
      <input id="cemail" type="email" name="email" required data-msg-email="Enter a valid email account!">
    </p>
    <p>
      <input class="submit" type="submit" value="Submit">
    </p>
  </fieldset>
</form>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/jquery-validation@1.17.0/dist/jquery.validate.js"></script>
<script>
$("#commentForm").validate();
</script>

你可以创建自己的函数

function emailValidate(email){
    var check = "" + email;
    if((check.search('@')>=0)&&(check.search(/\./)>=0))
        if(check.search('@')<check.split('@')[1].search(/\./)+check.search('@')) return true;
        else return false;
    else return false;
}

alert(emailValidate('your.email@yahoo.com'));

<script type="text/javascript">
    $(document).ready(function() {
      $('.form_error').hide();
      $('#submit').click(function(){
           var name = $('#name').val();
           var email = $('#email').val();
           var phone = $('#phone').val();
           var message = $('#message').val();
           if(name== ''){
              $('#name').next().show();
              return false;
            }
            if(email== ''){
               $('#email').next().show();
               return false;
            }
            if(IsEmail(email)==false){
                $('#invalid_email').show();
                return false;
            }

            if(phone== ''){
                $('#phone').next().show();
                return false;
            }
            if(message== ''){
                $('#message').next().show();
                return false;
            }
            //ajax call php page
            $.post("send.php", $("#contactform").serialize(),  function(response) {
            $('#contactform').fadeOut('slow',function(){
                $('#success').html(response);
                $('#success').fadeIn('slow');
               });
             });
             return false;
          });
      });
      function IsEmail(email) {
        var regex = /^([a-zA-Z0-9_\.\-\+])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
        if(!regex.test(email)) {
           return false;
        }else{
           return true;
        }
      }
  </script>

<form action="" method="post" id="contactform">
                            <table class="contact-table">
                              <tr>
                                <td><label for="name">Name :</label></td>
                                <td class="name"> <input name="name" id="name" type="text" placeholder="Please enter your name" class="contact-input"><span class="form_error">Please enter your name</span></td>
                              </tr>
                              <tr>
                                <td><label for="email">Email :</label></td>
                                <td class="email"><input name="email" id="email" type="text" placeholder="Please enter your email" class="contact-input"><span class="form_error">Please enter your email</span>
                                  <span class="form_error" id="invalid_email">This email is not valid</span></td>
                              </tr>
                              <tr>
                                <td><label for="phone">Phone :</label></td>
                                <td class="phone"><input name="phone" id="phone" type="text" placeholder="Please enter your phone" class="contact-input"><span class="form_error">Please enter your phone</span></td>
                              </tr>
                              <tr>
                                <td><label for="message">Message :</label></td>
                                <td class="message"><textarea name="message" id="message" class="contact-input"></textarea><span class="form_error">Please enter your message</span></td>
                              </tr>
                              <tr>
                                <td></td>
                                <td>
                                  <input type="submit" class="contactform-buttons" id="submit"value="Send" />
                                  <input type="reset" class="contactform-buttons" id="" value="Clear" />
                                </td>
                              </tr>
                            </table>
     </form>
     <div id="success" style="color:red;"></div>

如果你正在使用jquery验证

我创建了一个方法emailCustomFormat，使用正则表达式为我的自定义格式，你可以改变它来满足你的要求

jQuery.validator.addMethod("emailCustomFormat", function (value, element) {
        return this.optional(element) || /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/.test(value);
    }, abp.localization.localize("Please_enter_valid_email_message"));// localized message based on current language

然后你可以这样使用它

$("#myform").validate({
  rules: {
    field: {
      required: true,
      emailCustomFormat : true
    }
  }
});

这个正则表达式接受

abc@abc.abc, abc@abc.abcd 但不是这个

abc@abc ， abc@abc.a， abc@abc.abcde

希望这对你有所帮助

<!-- Dont forget to include the jQuery library here -->
<script type="text/javascript" src="jquery-1.3.2.min.js"></script>
<script type="text/javascript">

$(document).ready(function() {

    $("#validate").keyup(function(){

        var email = $("#validate").val();

        if(email != 0)
        {
            if(isValidEmailAddress(email))
            {
                $("#validEmail").css({
                    "background-image": "url('validYes.png')"
                });
            } else {
                $("#validEmail").css({
                    "background-image": "url('validNo.png')"
                });
            }
        } else {
            $("#validEmail").css({
                "background-image": "none"
            });         
        }

    });

});

function isValidEmailAddress(emailAddress) {
    var pattern = new RegExp(/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(@\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i);
    return pattern.test(emailAddress);
}

</script>

<style>
    #validEmail
    {
        margin-top: 4px;
        margin-left: 9px;
        position: absolute;
        width: 16px;
        height: 16px;
    }

    .text
    {
        font-family: Arial, Tahoma, Helvetica;
    }
</style>

    <title>Live Email Validation with jQuery Demo</title>
</head>
<body>
    <div class="text"><h1>Reynoldsftw.com - Live Email Validation</h1><h2>Type in an email address in the box below:</h2></div>
    <div><input type="text" id="validate" width="30"><span id="validEmail"></span></div>
    <div class="text"><P>More script and css style

: www.htmldrive.net

来源:htmldrive.com