JavaScript regex for email fails. Why?

Question

This is a ready-baked regex that I got from the internet just to see how regex works in JavaScript (and jQuery). Here is my script:

<script>
    $(document).ready(function(){
        var regexp = new RegExp(([\w-\.]+)@((?:[\w]+\.)+)([a-zA-Z]{2,4}));
        $("#submit").click(function(){
            var result = regexp.test( $("#email").val() );
            if(result){
                $("form").submit();
            }else{
                alert("Invalid Email Address");
            }
        });
    });
</script>

However, the form always submits despite entering a wrong email address.

I have read on how test() works. It know that it returns the right answer and then advances a pointer to the next value. So if it returns true, the pointer points to false. I do not see how that can be a problem here.

what is wrong here? :)

HTML:

<body>
    <center>
        <form name="subscription" method="post" action="http://www.cs.tut.fi/cgi-bin/run/~jkorpela/echo.cgi">
            <input type="text" name="email" size="30" id="email"></input>
            <button id="submit">Submit</button>
        </form>
    </center>
</body>

@PratikJoshi With all due respect, I feel you are being a little disrespectful here. — An SO User, Mar 31 '14 at 06:45
Please check console errors first-> Uncaught SyntaxError: Unexpected token ILLEGAL — Pratik Joshi, Mar 31 '14 at 06:47
Visit http://stackoverflow.com/questions/46155/validate-email-address-in-javascript — Satpal, Mar 31 '14 at 06:51
@LittleChild , With all respect , Why do you feel so ?I mean if you expect good answer ,then you should not assume ,that we know your html, So please post jsfiddle ,and include HTML. — Pratik Joshi, Mar 31 '14 at 06:56

Amit Joki · Answer 1 · 2014-03-31T07:05:05.523

2

Your regex initialization should be string and it should be escaped.

var regexp = new RegExp("([\\w\\.-]+)@((?:[\\w]+\\.)+)([a-zA-Z]{2,4})");

You can also use:

var regexp = /([\w\.-]+)@((?:[\w]+\.)+)([a-zA-Z]{2,4})/;

edited Mar 31 '14 at 07:05

answered Mar 31 '14 at 06:45

Amit Joki

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ah ! I didnt see the tutorial mention that :) – An SO User Mar 31 '14 at 06:46
uhm... still doesnt solve the problem. – An SO User Mar 31 '14 at 06:47
what do you mean by not solving the problem? – Amit Joki Mar 31 '14 at 06:48
still it shows console error – Pratik Joshi Mar 31 '14 at 06:48
@AmitJoki : `Range out of order in character class ` – An SO User Mar 31 '14 at 06:49

score 2 · Answer 2 · answered Mar 31 '14 at 06:46

2

Use this instead?

<input type="email" />

answered Mar 31 '14 at 06:46

MrProgram

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Yes, that is an option but the idea is to see how regex work. That's all :) – An SO User Mar 31 '14 at 06:46

Sahil Mittal · Accepted Answer · 2014-03-31T06:57:56.253

2

You need to double escape your Regex. Try this-

var regexp = new RegExp("([\\w-\\.]+)@((?:[\\w]+\\.)+)([a-zA-Z]{2,4})");

Edit

It is always helpful to log the result so that you see if your regexp string is correct, eg:

console.log("([\\w-\\.]+)@((?:[\\w]+\\.)+)([a-zA-Z]{2,4})");
console.log("([\w-\.]+)@((?:[\w]+\.)+)([a-zA-Z]{2,4})");

edited Mar 31 '14 at 06:57

answered Mar 31 '14 at 06:49

Sahil Mittal

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Done !! Working !! :-) – An SO User Mar 31 '14 at 06:53
Few more minutes to go :) – An SO User Mar 31 '14 at 06:55

score 0 · Answer 4 · answered Mar 31 '14 at 06:49

0

write it a regex (note the /)

Regex: var regexp = new RegExp(/([\w-\.]+)@((?:[\w]+\.)+)([a-zA-Z]{2,4})/);

answered Mar 31 '14 at 06:49

VeXii

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score 0 · Answer 5 · answered Mar 31 '14 at 06:51

0

In Html5, There is a new attribute type="email" is available.

Instead of using input type="text"

Please try this!

answered Mar 31 '14 at 06:51

TELMILA

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score 0 · Answer 6 · answered Mar 31 '14 at 08:20

0

Please try like this:

var regex = /^[a-zA-Z0-9äöüÄÖÜ._-]+@[a-zA-Z0-9äöüÄÖÜ.-]+.[a-zA-Z]{2,4}$/;

answered Mar 31 '14 at 08:20

TELMILA

83
9

JavaScript regex for email fails. Why?

6 Answers6