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.

Answer 2

You can just use below code

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;   // return NO to not change text
 {
  if(textField.tag == 111)
    {
    if([self MobileNumberValidate:string] == TRUE)
    return YES;
    else
    return NO;
}
return YES;
}

#pragma mark - Mobile Number validation
- (BOOL)MobileNumberValidate:(NSString*)number
{
NSString *numberRegEx = @"[0-9]";
NSPredicate *numberTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", numberRegEx];
if ([numberTest evaluateWithObject:number] == YES)
    return TRUE;
else
    return FALSE;
}