Trying to format a UITextField to behave like a currency calculator for only numeric input in iOS

format_uiTextFieldCalculator.md

e.g. when entering the number "1234.56".

1. $ 0.00.

2. $ 0.01.

3. $ 0.12.

4. $ 1.23.

5. $ 12.34.

6. $ 123.45.

7. $ 1,234.56

        -(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
        
              NSString *cleanCentString = [[textField.text componentsSeparatedByCharactersInSet: [[NSCharacterSet decimalDigitCharacterSet] invertedSet]] componentsJoinedByString:@""];
                NSInteger centValue = [cleanCentString intValue];
                NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
                NSNumber *myNumber = [f numberFromString:cleanCentString];
                NSNumber *result;
                
                if([textField.text length] < 16){
                    if (string.length > 0)
                    {
                        centValue = centValue * 10 + [string intValue];
                        double intermediate = [myNumber doubleValue] * 10 +  [[f numberFromString:string] doubleValue];
                       result = [[NSNumber alloc] initWithDouble:intermediate];
                    }
                    else
                    {
                        centValue = centValue / 10;
                        double intermediate = [myNumber doubleValue]/10;
                        result = [[NSNumber alloc] initWithDouble:intermediate];
                    }
                    
                    myNumber = result;
                     NSLog(@"%ld ++++ %@", (long)centValue, myNumber);
                        NSNumber *formatedValue;
                        formatedValue = [[NSNumber alloc] initWithDouble:[myNumber doubleValue]/ 100.0f];
                        NSNumberFormatter *_currencyFormatter = [[NSNumberFormatter alloc] init];
                        [_currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
                        textField.text = [_currencyFormatter stringFromNumber:formatedValue];
                        return NO;
                }else{
                
                    NSNumberFormatter *_currencyFormatter = [[NSNumberFormatter alloc] init];
                    [_currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
                    textField.text = [_currencyFormatter stringFromNumber:00];
                    
                    UIAlertView *alert = [[UIAlertView alloc]initWithTitle: @"Deposit Amount Limit"
                                                                   message: @"You've exceeded the deposit amount limit. Kindly re-input amount"
                                                                  delegate: self
                                                         cancelButtonTitle:@"Cancel"
                                                         otherButtonTitles:@"OK",nil];
                                                         
                    [alert show];
                    return NO;
                }
                return YES;
        }