JavaScript Regular Expression Email Validation

javascript regex
azamsharp picture azamsharp · Jun 2, 2009 · Viewed 365.4k times · Source

This code is always alerting out "null", which means that the string does not match the expression.

var pattern = "^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$"; 

function isEmailAddress(str) {

    str = "[email protected]";      

    alert(str.match(pattern)); 
    return str.match(pattern);    

}

Answer

James picture James · Jun 2, 2009

If you define your regular expression as a string then all backslashes need to be escaped, so instead of '\w' you should have '\\w'.

Alternatively, define it as a regular expression:

var pattern = /^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$/;

BTW, please don't validate email addresses on the client-side. Your regular expression is way too simple to pass for a solid implementation anyway.

See the real thing here: http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html

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