NSPredicate for mobile number validation

Question

How to validate a phone number (NSString *) by NSPredicate?

Rules:

minimum 10 digits

maximum 10 digits

the first digit must be 7,8 or 9 Thanks

Answer 1

An NSPredicate based on a regular expression will fit your requirements.

NSString *stringToBeTested = @"8123456789";

NSString *mobileNumberPattern = @"[789][0-9]{9}";
NSPredicate *mobileNumberPred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", mobileNumberPattern];

BOOL matched = [mobileNumberPred evaluateWithObject:stringToBeTested];

You don't need to keep the pattern in a string by itself, but regexes are complicated enough already so it makes the overall code clearer if you keep it out of the NSPredicate format string.