I am trying to write out a RegExp pattern to validate an e-mail. I have googled but can't seem to find a definite answer but what characters/symbols are not allowed in a valid email address?

Is RegExp the way to go to validate an email format? I started off using the below way, but then started looking into RegExp:

function validateEmail( email:String ):Boolean
{
    var i:int = -1;
    var n:int = email.length;
    
    if( n <= 6 )
    {
        return false;
    }
 
    var invalidChar:String = "~^*|,\":<>[]{}`\';()&$#%";
    
    while( ++ i < n )
    {
        if( invalidChar.indexOf( email.charAt( i ) ) != -1 )
        {
            return false;
        }
    }
    
    return true;
} 

I'm going to eat your brain and gain your knowledge.

[Isocase]

Did some research and I was finally able to find information on wikipedia. Here is the URL if anyone ever needs to know this information

http://en.wikipedia.org/wiki/E-mail_address

[Fernando]

function isValidEmail(email:String):Boolean {
    var emailExpression:RegExp = /^[a-z][\w.-]+@\w[\w.-]+\.[\w.-]*[a-z][a-z]$/i;
    return emailExpression.test(email);
} 

trace (isValidEmail("user@ultrashock.com")); // true
trace (isValidEmail("test@@tester.com")); // false 
 

[Isocase]

Thanks Fernando

I was wondering and did some research but couldn't find the answer I was looking for. In AS3 how processor intensive is using RegExp compared to using substring or something like that.

Example:

Lets say I am building a form and I want to remove white space after the subject. Would it be best to use a RegExp or just loop through the string until it finds the space then use substring to shorten?

[Fernando]

RegExp is a hell lot faster than a substring way of doing smth.