How to specify decimal places when formatting NSNumber objects?

Question

I\'m using the following piece of Objective-C code to format a NSNumber, and it works fine most of the time, but it doesn\'t quite do what I want when the NSNumber object ho

Answer 1

I believe what you are looking for is: "%.2f"

Worst case scenario, you can split the value, check if there is anything after the decimal. If there isn't add the 00 by hand?

Answer 2

Your format string should have a "0" for each decimal place you want to always exist.

[formatter setFormat:@"###.00"];

for "55.23" and ".23" and ".20"

[formatter setFormat:@"##0.00"];

for "55.23" and "0.23" and "0.20"

See Number Format String Syntax (Mac OS X Versions 10.0 to 10.3)

Or you can use a 10.4 formatter with - setMinimumFractionDigits: and - setMaximumFractionDigits: with both set to 2.

Answer 3

You might be better off with localizedStringWithFormat, like so...

[UILabel alloc] initWithFrame:CGRectMake(80.0f, 90.0f, 225.0f, 40.0f)];
label.backgroundColor = [UIColor clearColor];
label.textColor = [UIColor whiteColor];
int bytes = 1024 * 1024;
label.text = [NSString localizedStringWithFormat:@"0.00 MB of %.2f MB", ([self.totalFileSize floatValue] / bytes)];

And of course, bytes could be a const unsigned, and clearColor tends to be a performance hog, but those are issues for another thread.