NSNumberFormatter stringFromNumber returning 1,000,000,000 for input 999999999

Question

When I try to convert number 999999999 to string using NSNumberFormatter, I am getting wrong value. It returns 1,000,000,000 instead of 999,999,999.

Here is the code that I use.

 NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setUsesSignificantDigits:YES];
[numberFormatter setNumberStyle: NSNumberFormatterCurrencyStyle];
[numberFormatter setLocale:[NSLocale systemLocale]];
[numberFormatter setCurrencySymbol:@""];

numberAsString = [numberFormatter stringFromNumber:[NSDecimalNumber decimalNumberWithString:@"999999999" ]];
NSLog(@"Currency String %@",numberAsString);

Why do you need to convert it to a decimal number, pass it through a formatter (that's configured as a currency formatter??), and pass it back into a string? — Schemetrical, Apr 09 '15 at 12:34
offtopic: use dot notation for properties as suggested in many objc styleguide's — CarlJ, Apr 09 '15 at 12:47

score 2 · Accepted Answer · answered Apr 09 '15 at 12:34

2

You specified to use significant digits, but didn't say how many to use. For example, if you add the following, you get the result you were expecting:

[numberFormatter setMaximumSignificantDigits:9];

So, if you're going to use significant digits, specify how many you want to use. Or don't use significant digits at all.

answered Apr 09 '15 at 12:34

Rob

415,655
72
787
1,044

@matthias , Rob setting significant digits solved my issue. Thanks a lot. :) – arundevma Apr 09 '15 at 12:49

score 2 · Answer 2 · edited May 23 '17 at 12:28

You enabled usesSignificantDigits. Default value for maximumSignificantDigits is 6. Which means every number with more than 6 significant digits will be rounded to have less than 6 significant digits.

999 999 999 has 9 significant digits. So it will be rounded to 1 000 000 000

You probably don't want to set usesSignificantDigits at all.

Here is a good explanation what significant digits do with NSNumberFormatter.

NSNumberFormatter stringFromNumber returning 1,000,000,000 for input 999999999

2 Answers2