Restrict UITextField size

cocoa-touch, objective-c, uitextfield

Solution

Here is a code sample to limit the size of a UITextField:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
  if ([[textField text] length] + [string length] - range.length > MAX_LENGTH) {
    return NO;
  } else {
    return YES; 
  }
}

Problem

How can I limit the number of characters in a UITextField? I.e if I limit it to 10 characters, the user will be unable to enter more than 10. Also I want to prevent him from entering some special characters like +, =, etc. How would I do this?

Original source

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