How to make a regular Expression for name Validation - ios

Question

I want to make a regular expression in which user can only enter alphabets.
I am using this piece of code to validate the UITextField.
I am validating the code in shouldChangeCharactersInRange method.
NSString *regex = #"[a-zA-Z]";
NSPredicate *testRegex = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", regex];
if(![testRegex evaluateWithObject:string])
return NO;
It is working fine but I can not delete using BacKspace button As my RegEx doesn't allow this.
How can I make a regular expression which supports alphabets and allow deletion.

Answer 1

Try this out:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)iRange replacementString:(NSString *)iText {
NSString *newString = [iTextView.text stringByReplacingCharactersInRange:iRange withString:iText];
NSString *abnRegex = #"[A-Za-z]+";
NSPredicate *abnTest = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", abnRegex];
return ([abnTest evaluateWithObject:newString] || newString.length == 0);
}

Answer 2

Can you try with this (Just a work around) :
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if (range.length > 0)
{
// We're deleting
return YES;
}
else
{
// We're adding
NSString *regex = #"[a-zA-Z]";
NSPredicate *testRegex = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", regex];
if(![testRegex evaluateWithObject:string])
return NO;
else
return YES;
}