Regular expression for email not working

Question

I am putting validation on email field but it shows error of invalid even where the email is typed in correct format.

Code

<script type="text/javascript">
function formvalidate(){
    var email=document.signup_form.email.value;

    var check_email= RegExp("^[A-Z0-9._-]+@[A-Z0-9.-]+\.[A-Z0-9.-]+$");

    if(email=="")
    {
        alert("cannot be empty!");
        document.signup_form.email.focus();
        return false;
    }

    else if(!check_email.test(email))
    {
        alert("enter valid email address!");
        document.signup_form.email.focus();
        return false;
    }
    else
    {
        return true;
    }
}

</script>

Thanks

Possible duplicate of [Validate email address in JavaScript?](http://stackoverflow.com/questions/46155/validate-email-address-in-javascript) — Mehdi Dehghani, Nov 14 '16 at 11:35

score 1 · Answer 1 · edited Mar 16 '21 at 06:52

1

1- Use this regular expressions instead

\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

2- Change this if (!check_email.test(email)) to

if (check_email.test(email))

edited Mar 16 '21 at 06:52

Mehdi Dehghani

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answered Jun 29 '16 at 06:39

Ali Niazi

19
3

I used this expression but still shows invalid error on valid email (firstname@gmail.com) – Natha Odedara Jun 29 '16 at 06:43

score 1 · Answer 2 · answered Jun 29 '16 at 06:46

1

try this function

function validateEmail(elementValue) {
    var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
    return emailPattern.test(elementValue);
}

Please refer this fiddle : http://jsfiddle.net/gabrieleromanato/Ra85j/

answered Jun 29 '16 at 06:46

NikuNj Rathod

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score 0 · Answer 3 · answered Jun 29 '16 at 06:41

Try this fuction

     function isEmail(inputString) {
     var regExpEmail = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
         try {
              return regExpEmail.test(inputString.value);
             }
        catch (e) {
              return false;
               }

}

score 0 · Answer 4 · answered Jun 29 '16 at 06:41

Change var check_email= RegExp("^[A-Z0-9._-]+@[A-Z0-9.-]+\.[A-Z0-9.-]+$"); to a function like this:

function validateEmail(email) {
    var re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
}

score 0 · Answer 5 · edited May 23 '17 at 10:29

You regex is not correct, there are many things that you've not considered, like your regex accepts only capital letters, to include both capital and small letters you should use :

[a-zA-Z0-9]

not this :

[A-Z0-9]

You can use this regex for validating email :

/^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/

read this for details

score 0 · Answer 6 · answered Jun 29 '16 at 06:44

0

Source and some tests

You can use this regex for email:

RegExp('\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b', 'i')

answered Jun 29 '16 at 06:44

Justinas

41,402
5
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score 0 · Answer 7 · answered Jun 29 '16 at 06:52

try this example : email validation using JQuery

function validateEmail(email) {
  var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
  return re.test(email);
}

function validate() {
  $("#emailvalidate").text("");
  var email = $("#email").val();
  if (validateEmail(email)) {
    $("#emailvalidate").text(email + " is valid");
    $("#emailvalidate").css("color", "green");
  } else {
    $("#emailvalidate").text(email + " is not valid");
    $("#emailvalidate").css("color", "red");
  }
  return false;
}
$("form").bind("submit", validate);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<form>
  <p>Enter an email address:</p>
  <input id='email'>
  <button type='submit' id='btn'>Validate</button>
</form>
<h2 id='emailvalidate'></h2>

Vikash Kumar · Answer 8 · 2016-06-29T07:21:56.690

Try this code -

function formvalidate()
{
    var email = document.signup_form.email.value;

    var check_email = RegExp("^([a-z0-9\\+_\\-]+)(\\.[a-z0-9\\+_\\-]+)*@([a-z0-9\\-]+\\.)+[a-z]{2,6}$", 'ig');

    if(email == "")
    {
        alert("cannot be empty!");
        document.signup_form.email.focus();
        return false;
    }

    else if(!check_email.test(email))
    {
        alert("enter valid email address!");
        document.signup_form.email.focus();
        return false;
    }
    else
    {
        return true;
    }
}

<form name="signup_form">
  <input type="text" name="email" value="" />
  <input type="button" name="validate" value="Validate" onclick="formvalidate()"/>
</form>

score 0 · Answer 9 · answered Nov 08 '22 at 20:10

I am using below regex to validate email pattern. Regex is not 100% solution to validate an email, better use email verification. Regex can help to validate format or pattern only.

Jsfiddle: DEMO

Jsfiddle: Regex check and sample email DEMO

function validateEmail(elementValue) {
  document.getElementById('error').innerHTML = elementValue + ', email is incorrect';
  var emailPattern = /^[a-z0-9](?:[a-z0-9]+\.)*(?!.*(?:__|\\.\\.))[a-z0-9_]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9](?!\.)){0,61}[a-zA-Z0-9]?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9](?!$)){0,61}[a-zA-Z0-9]?)|(?:(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])))$/;
  if (emailPattern.test(elementValue)) {
    document.getElementById('error').innerHTML = elementValue + ', email is correct';
  }
  return false;
}

#error {
  color: red;
  font-size: 2rem;
}

input[type='email'] {
  padding: 5px;
  width: 300px;
  border-color: blue;
  font-size: 16px;
}

<form name="signup_form">
  <input type="email" value="" onblur="validateEmail(this.value)">
  <br />
  <lable id="error"></lable>
</form>

score -1 · Answer 10 · answered Jun 29 '16 at 07:30

-1

Change your regular expression to below

^[a-zA-Z0-9._-]+@[A-Za-z0-9.-]+\.[a-zA-Z0-9.-]+$

Hope this helps :)

answered Jun 29 '16 at 07:30

Mr.7

2,292
1
20
33

Regular expression for email not working

10 Answers10