Password validation in UITextField which disallowed some special character

Question

I'm having 1 UITextfield for password in my iPhone application. I want to validate this textfield with the following validation. * Must be at least 6 characters * Must contain alphanumeric value * does not allowed some special characters are $#@~| how can I restrict the UITextField with above requirements. please anyone help me out to do this..

plenty of examples present on SO you could search, [look](https://www.google.co.in/?gws_rd=ssl#q=uitextfield+alphanumeric+validation). — vaibhav, Feb 01 '17 at 10:02
Possible duplicate of [Password validation in UITextField in iOS](http://stackoverflow.com/questions/15132276/password-validation-in-uitextfield-in-ios) — Prissy Eve, Feb 01 '17 at 10:10
I want to restrict this special character $#@~| and also space's are not allowed. — Narendra Jagne, Feb 01 '17 at 11:33
What kind of application does not allow special characters in password? — Klaus Byskov Pedersen, Feb 01 '17 at 13:50

score 0 · Answer 1 · answered Feb 01 '17 at 11:08

As simple as below.

NSString *passwordRegex = @"^.*(?=.{6,})(?=.*\\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$!&]).*$";
NSPredicate *passwordPred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", passwordRegex];

if (![passwordPred evaluateWithObject:passwordTF.text]) {
    [self.view makeToast:@"Password must be at least 6 character, containing lowercase letter, one uppercase letter, digits, and special character (!@#$&)" duration:2.0 position:@"bottom"];
}

I does not allowed this special characters !@#$& – Narendra Jagne Feb 01 '17 at 11:16 — Narendra Jagne, Feb 01 '17 at 11:16

score 0 · Answer 2 · answered Feb 01 '17 at 13:48

Check with below methods.Just now I tried and it works.

- (void)textFieldDidEndEditing:(UITextField *)textField{
if([textField.text length]<5){
    [self showAlertController:@"Error" passMessage:@"Must be atleast 6 characters"];
}
NSCharacterSet * charSet = [[NSCharacterSet characterSetWithCharactersInString:@" ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_."] invertedSet];
if ([textField.text rangeOfCharacterFromSet:charSet].location != NSNotFound){
    [self showAlertController:@"Error" passMessage:@"Must not allow special characters $#@~|"];
}

}

-(BOOL)textFieldShouldReturn:(UITextField *)textField{
[textField resignFirstResponder];
return YES;
}

-(void)showAlertController:(NSString *)title passMessage:(NSString *)message{
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction* ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil];
    [alert addAction:ok];
    [self presentViewController:alert animated:YES completion:nil];
}

score -1 · Answer 3 · answered Feb 01 '17 at 10:24

  int numberofCharacters = 0;

  BOOL lowerCaseLetter,upperCaseLetter,digit,specialCharacter = 0;

  if([textField.text length] >= 6){

  for (int i = 0; i < [textfield.text length]; i++) 
  {
     unichar c = [textfield.text characterAtIndex:i];
     if(!lowerCaseLetter)
     {
       lowerCaseLetter = [[NSCharacterSet lowercaseLetterCharacterSet] characterIsMember:c];
     }
     if(!upperCaseLetter)
     {
       upperCaseLetter = [[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:c];
     }
     if(!digit)
     {
        digit = [[NSCharacterSet decimalDigitCharacterSet] characterIsMember:c];
     }
     if(!specialCharacter)
     {
        specialCharacter = [[NSCharacterSet symbolCharacterSet] characterIsMember:c];
     }
  }

    if(specialCharacter && digit && lowerCaseLetter && upperCaseLetter)
    {
       //do what u want
    }
    else
    { 
       //Error" Please Ensure that you have at least one lower case letter,   one upper case letter, one digit and one special character"
    }
  else{
   //error number of char must be more or equal to 6
}

Password validation in UITextField which disallowed some special character

3 Answers3