iOS: formatting decimal numbers

Question

I have an NSDecimalNumber representing a money amount. I want to print it as \"999 999 999 999 999 999,00\", regardless on the locale. How do I do that?

Answer 1

Try this:

    NSLocale *usLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"US"];

    NSNumberFormatter *frm = [[NSNumberFormatter alloc] init];
    [frm setNumberStyle:NSNumberFormatterDecimalStyle];
    [frm setMaximumFractionDigits:2];
    [frm setMinimumFractionDigits:2];
    [frm setLocale:usLocale];
    NSString *formattedNumberStr = [frm stringFromNumber:[NSNumber numberWithFloat:floatToRound]];

    [frm release];
[usLocale release];

    return formattedNumberStr;

Answer 2

I had the same problem. I was told that NSNumberFormatter converts everything to a double first. How did I solve it? It's easy, just write your own formatter.

1. First round the decimal to 2 decimal digits.
2. Get its description as a string.
3. Find decimal point (.) in the string and replace it with the one you want.
4. After every three digits from the decimal point to the left, insert a grouping separator.