Question

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];

    if (string.length == 0) {
        return YES;
    }

    [numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
    NSNumber* candidateNumber;
    NSString* candidateString = [textField.text stringByReplacingCharactersInRange:range withString:string];
    range = NSMakeRange(0, [candidateString length]);
    [numberFormatter getObjectValue:&candidateNumber forString:candidateString range:&range error:nil];
    if (([candidateString length] > 0) && (candidateNumber == nil || range.length < [candidateString length])) {
        return NO;
    }
    else
    {
        return YES;
    }

Hi, with this code i can insert only decimal values in a textfield.
The decimal separator is a comma “,”
How do I change it to a dot “.” ?

Thanks

Answer 1

There is a little thing called Localization. Every language uses a different character as a decimal separator. Where English uses a decimal point, other languages use a comma (or other characters).

When you create a NSNumberFormatter it uses the system locale (NSLocale instance) to decide about the decimal separator (and grouping separator and other things).
If you want a fixed behavior, then just set a different locale using [NSNumberFormatter setLocale:]

Also note there is one special kind of locale
[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"] which defines a special locale which cannot be changed by user settings and is always the same.

In this case, using a NSNumberFormatter is not the best idea. This is one of the cases when you want to use a regular expression.