JavaScript regular expression validation for domain name?

Question

How to check a valid domain name and username with regular expression in JavaScript?

function validate()
{
    var         


        

Answer 1

function CheckIsValidDomain(domain) { 
    var re = new RegExp(/^((?:(?:(?:\w[\.\-\+]?)*)\w)+)((?:(?:(?:\w[\.\-\+]?){0,62})\w)+)\.(\w{2,6})$/); 
    return domain.match(re);
} 

try this its work for me.

Answer 2

Don't mix up the RegExp constructor with regex literals. Use either

/^[a-zA-Z0-9._-]+\\[a-zA-Z0-9.-]$/

or

new RegExp("^[a-zA-Z0-9._-]+\\\\[a-zA-Z0-9.-]$");

Not sure what the backslash does in there, btw. Did you want to match a dot? In literal, use \., in string use \\..

Answer 3

This maybe slightly off-topic but after searching the internet for several hours and trying out various RegExp's (non of which would work for me). I decided to write my own function that would take a list of valid TLD extensions and run a validation against them. So for anyone who is having a similar problem, please check out my Javascript function:

function domainCheck(dom) {
    // convert input to lowercase.
    dom = dom.toLowerCase();
    // find the first occurance of '.'
    pos = dom.indexOf(".");
    // Using the first occurance of '.'
    // find the extension submitted.
    tld = dom.substring(pos);
    switch(tld) {
        // TLD's to accept.
        case '.com': return true; break;
        case '.co.uk': return true; break;
        case '.eu': return true; break;
        case '.io': return true; break;
        case '.co': return true; break;
        case '.net': return true; break;
        default: return false;
    }
}

I have created a demo using this function here: http://jsfiddle.net/netfox/MhPG8/19/embedded/result/

Answer 4

This code support sub-domains too:

^(([a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9]|[a-zA-Z0-9])\.)*[a-zA-Z0-9][a-zA-Z0-9-]{1,61}[a-zA-Z0-9]\.[a-zA-Z]{2,}$

Answer 5

Use this:

<script>
    function frmValidate() {
        var val = document.frmDomin.name.value;
        if (/^[a-zA-Z0-9][a-zA-Z0-9-]{1,61}[a-zA-Z0-9](?:\.[a-zA-Z]{2,})+$/.test(val)) {
            alert("Valid Domain Name");
            return true;
        } else {
            alert("Enter Valid Domain Name");
            val.name.focus();
            return false;
        }
    }
</script>

Answer 6

check this: http://shauninman.com/archive/2006/05/08/validating_domain_names

/^([a-z0-9]([-a-z0-9]*[a-z0-9])?\\.)+((a[cdefgilmnoqrstuwxz]|aero|arpa)|(b[abdefghijmnorstvwyz]|biz)|(c[acdfghiklmnorsuvxyz]|cat|com|coop)|d[ejkmoz]|(e[ceghrstu]|edu)|f[ijkmor]|(g[abdefghilmnpqrstuwy]|gov)|h[kmnrtu]|(i[delmnoqrst]|info|int)|(j[emop]|jobs)|k[eghimnprwyz]|l[abcikrstuvy]|(m[acdghklmnopqrstuvwxyz]|mil|mobi|museum)|(n[acefgilopruz]|name|net)|(om|org)|(p[aefghklmnrstwy]|pro)|qa|r[eouw]|s[abcdeghijklmnortvyz]|(t[cdfghjklmnoprtvwz]|travel)|u[agkmsyz]|v[aceginu]|w[fs]|y[etu]|z[amw])$/i