Saya tidak terlalu yakin bagaimana melakukan ini. Saya perlu memvalidasi alamat email menggunakan regex dengan sesuatu seperti ini:

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+(?:[A-Z]{2}|com|org|net|edu|gov|mil|biz|info|mobi|name|aero|asia|jobs|museum)

Maka saya perlu menjalankan ini dalam fungsi jQuery seperti ini:

$j("#fld_emailaddress").live('change',function() { 
var emailaddress = $j("#fld_emailaddress").val();

// validation here? 

if(emailaddress){}

// end validation

$j.ajax({  
        type: "POST",  
         url: "../ff-admin/ff-register/ff-user-check.php",  
        data: "fld_emailaddress="+ emailaddress,  
        success: function(msg)
        { 
            if(msg == 'OK') { 
            $j("#fld_username").attr('disabled',false); 
            $j("#fld_password").attr('disabled',false); 
            $j("#cmd_register_submit").attr('disabled',false); 
            $j("#fld_emailaddress").removeClass('object_error'); // if necessary
            $j("#fld_emailaddress").addClass("object_ok");
            $j('#email_ac').html('&nbsp;<img src="img/cool.png" align="absmiddle"> <font color="Green"> Your email <strong>'+ emailaddress+'</strong> is OK.</font>  ');
            } else {  
            $j("#fld_username").attr('disabled',true); 
            $j("#fld_password").attr('disabled',true); 
            $j("#cmd_register_submit").attr('disabled',true);  
            $j("#fld_emailaddress").removeClass('object_ok'); // if necessary
            $j("#fld_emailaddress").addClass("object_error");
            $j('#email_ac').html(msg);
            }
        }
     });
});

Kemana perginya validasi dan apa ekspresinya?

PEMBARUAN

• http://so.lucafilosofi.com/jquery-validate-e-mail-address-regex/
• menggunakan regex baru
• menambahkan dukungan untuk tag Alamat (+ tanda)

function isValidEmailAddress(emailAddress) {
    var pattern = /^([a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+(\.[a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)*|"((([ \t]*\r\n)?[ \t]+)?([\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|\\[\x01-\x09\x0b\x0c\x0d-\x7f\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))*(([ \t]*\r\n)?[ \t]+)?")@(([a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|[a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF][a-z\d\-._~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]*[a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])\.)+([a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF][a-z\d\-._~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]*[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])\.?$/i;
    return pattern.test(emailAddress);
}

if( !isValidEmailAddress( emailaddress ) ) { /* do stuff here */ }

• CATATAN: perlu diingat bahwa tidak ada cek email regex 100% !

Ini solusi saya:

function isValidEmailAddress(emailAddress) {
    var pattern = new RegExp(/^[+a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/i);
    // alert( pattern.test(emailAddress) );
    return pattern.test(emailAddress);
};

Menemukan RegExp di sini: http://mdskinner.com/code/email-regex-and-validation-jquery

$(document).ready(function() {

$('#emailid').focusout(function(){

                $('#emailid').filter(function(){
                   var emil=$('#emailid').val();
              var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
            if( !emailReg.test( emil ) ) {
                alert('Please enter valid email');
                } else {
                alert('Thank you for your valid email');
                }
                })
            });
});

Lolz ini jauh lebih baik

    function isValidEmailAddress(emailAddress) {
        var pattern = new RegExp(/^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/);
        return pattern.test(emailAddress);
    };

Saya akan merekomendasikan Anda menggunakan plugin jQuery untuk Verimail.js .

Mengapa?

• Validasi IANA TLD
• Validasi sintaksis (menurut RFC 822)
• Saran pengejaan untuk TLD dan domain email paling umum
• Tolak domain akun email sementara seperti mailinator.com

Bagaimana?

Sertakan verimail.jquery.js di situs Anda dan gunakan fungsinya:

$("input#email-address").verimail({
    messageElement: "p#status-message"
});

Jika Anda memiliki formulir dan ingin memvalidasi email saat kirim, Anda dapat menggunakan fungsi getVerimailStatus:

if($("input#email-address").getVerimailStatus() < 0){
    // Invalid email
}else{
    // Valid email
}

Javascript:

var pattern = new RegExp("^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$");
var result = pattern .test(str);

Regex tidak diperbolehkan untuk:

abc@gmail..com
abc@gmail.com..

Diizinkan untuk:

abc.efg@gmail.com
abc@gmail.com.my

Sumber: http://www.mkyong.com/regular-expressions/10-java-regular-expression-examples-you-should-know/

Kita juga dapat menggunakan persamaan reguler (/^([\w.-[+)@([\w-[+)((.(\w){2,3})+)$/i) untuk memvalidasi alamat email formatnya benar atau tidak.

var emailRegex = new RegExp(/^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$/i);
 var valid = emailRegex.test(emailAddress);
  if (!valid) {
    alert("Invalid e-mail address");
    return false;
  } else
    return true;

Coba ini

function isValidEmailAddress(emailAddress) {
    var pattern = new RegExp(/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/);
    return pattern.test(emailAddress);
};

Anda dapat menggunakan fungsi ini

 var validateEmail = function (email) {

        var pattern = /^([a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+(\.[a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)*|"((([ \t]*\r\n)?[ \t]+)?([\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|\\[\x01-\x09\x0b\x0c\x0d-\x7f\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))*(([ \t]*\r\n)?[ \t]+)?")@(([a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|[a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF][a-z\d\-._~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]*[a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])\.)+([a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF][a-z\d\-._~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]*[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])\.?$/i;


        if (pattern.test(email)) {
            return true;
        }
        else {
            return false;
        }
    };

Metode asli:

$("#myform").validate({
 // options...
});

$.validator.methods.email = function( value, element ) {
  return this.optional( element ) || /[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}/.test( value );
}

Sumber: https://jqueryvalidation.org/jQuery.validator.methods/