I just spent a lot of time doing something that would have been ridiculously easy with Cocoa’s NSPredicate : checking an email address to know if it is valid, before sending something to it. NSPredicate is not available on the iPhone.

I used instead RegexKitLite, which in turn uses libicucore, this time available on your iPhone, to check things. I just added the core class, and the RKLMatchEnumerator too, which adds a matchEnumeratorWithRegex to NSEnumerator. Et voilà !

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 NSEnumerator *matchEnumerator = NULL;  NSString    *emailRegEx = @"A-Z0-9a-z._%+-+@A-Za-z0-9.-+\\.A-Za-z{2,4}";

 matchEnumerator = emailAddress matchEnumeratorWithRegex:emailRegEx;

 //Validate email address  if (matchEnumerator nextObject == NULL) {    UIAlertView *alert = [UIAlertView alloc initWithTitle:@"" message:NSLocalizedString(@"EmailNotValid", @"No search") delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];    alert show;    alert release;    return;  }

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