Is there no Javascript LIKE statement?

Question

I want to do this but dont know how to do it in JavaScript.

if (Email == "*aol.com" || Email == "*hotmail*" || Email == "*gmail*" || Email == "*yahoo*") 
    {
     alert("No Hotmail, Gmail, Yahoo or AOL emails are allowed!");  
     return false;
    }

Any way around this?

Answer 1

Use the JavaScript REGEXP Object. Read the W3schools page or their tutorial for a few examples. If you have problems with either, just post those here and we'll get into more detail :)

var Email = '[email protected]';

var mail_pattern=new RegExp("/aol.com|hotmail|gmail|yahoo/");
if (mail_pattern.test(Email)) {
 alert("No Hotmail, Gmail, Yahoo or AOL emails are allowed!");  
}
else {
alert("mail ok")
}

Answer 2

First, I think your searches are a bit too generic. (e.g. what if someone has the email address, "[email protected]"?

Try this:

var notAllowed = /@(?:aol|hotmail|g(?:oogle)?mail|yahoo)\.com$/i;
// You may want to cover other domains under .co.uk etc.

if ( notAllowed.test(emailAddress) ) {
    alert("No Hotmail, Gmail, Yahoo or AOL emails are allowed!");  
    return false;
}

I have to ask, why are you disabling people from using these email addresses? (out of interest)

Also, this really should be done on the server-side (I'm assuming you're not using SSJS)

Answer 3

Best way is the REGEXP. Quick easy thing is indexOf method maybe, but it's so limited.

http://www.quirksmode.org/js/strings.html#indexof

Answer 4

Just for messin' with the people suggesting regexes, you could also do it programatically:

(I'm kinda suggesting you don't know JavaScript that well)

function validateEmail (email) {
    // Checks if whatever variable submitted is a string.
    // This line is NOT useful if you're sure of whatever being sent to the function,
    // but otherwise it'll save your ass for a runtime error.
    if (email.constructor != String) return false;

    // I'm not sure the search patterns are 100 % (they probably ain't),
    // but the @'s should make the search less generic.
    var emailsNotAllowed = ["@aol.com", "@hotmail.", "@live.", "@gmail.", "@google.", "@yahoo."];
    // Convert the email address to lower case, so you're sure nothing is going wrong with the patterns.
    email = email.toLowerCase();
    // Loop through all the patterns, and check if one of them matches the email address provided.
    for (var i = 0; i < emailNotAllowed.length; i++) {
        // The indexOf method will return zero if the string could not be found.
        // Otherwise, it will return a positive number, which in JavaScript validates to a true condition.
        if (email.indexOf(emailsNotAllowed[i])) {
            alert("No Hotmail, Gmail, Yahoo or AOL emails are allowed!");
            return false;
        }
    }
}

Hope it explains itself ;)

As also suggested, a check should be performed server side as an absolute minimum, otherwise you'll have no security. But, for usability, a client side check first is also good.