How to check if two text fields are the same? - ios

Question

I know this may be perceived as a duplicate but I promise you it is not.
Everybody has given an answer similar to this:
if ([_confirm.text isEqualToString: _password.text] || resultantLength2 < 3) {
textField.textColor = [UIColor redColor];
[_next setEnabled:NO];
}else{
[_next setEnabled:YES];
}
}
So why does this not work?
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if (textField == _confirm || textField == _password) {
int resultantLength2 = textField.text.length + string.length - range.length;
NSLog(#"Length After Additions And Subtractions Will Be: %i letters", resultantLength2);
if ([_confirm.text isEqualToString: _password.text] || resultantLength2 < 3) {
textField.textColor = [UIColor redColor];
[_next setEnabled:NO];
}else{
[_next setEnabled:YES];
}
}
return YES;
}
Where I have a next button that gets dissabled

Answer 1

What we actually want to do is compare the strings in the text fields AFTER the text has changed, but currently, we're using a method that is fired BEFORE the text changes and asks whether or not the change is okay.
We can do some tricks in this method to get it work right, but why not just check the values after they've changed?
In the view controller's viewDidLoad, add these two lines:
[_confirm addTarget:self action:#selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
[_password addTarget:self action:#selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
Now add the textFieldDidChange: method to compare the values in the textfield.
- (void)textFieldDidChange:(UITextField *)textField {
if (![_confirm.text isEqualToString: _password.text]) {
textField.textColor = [UIColor redColor];
[_next setEnabled:NO];
} else {
[_next setEnabled:YES];
}
}

Answer 2

Your problem is that you are in shouldChangeCharactersInRange, which is called before the text field is updated, but you are comparing the current value of _confirm.text
Also, your string comparison logic seems to be the wrong way around - you want NEXT enabled if the password is the same as the confirm I would think
I would try this -
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if (textField == _confirm) {
NSMutableString *newValue=[NSMutableString stringWithString:textField.text];
[newValue replaceCharactersInRange:range withString:string];
int resultantLength2 = newValue.length;
NSLog(#"Length After Additions And Subtractions Will Be: %i letters", resultantLength2);
if (([newValue isEqualToString: _password.text] == NO) || resultantLength2 < 3) {
textField.textColor = [UIColor redColor];
[_next setEnabled:NO];
}else{
textField.textColor = SOMETHING; // should reset text colour
[_next setEnabled:YES];
}
}
return YES;
}