Objective-C: How to format string as $ Price

问题:

Is their a built-in way of formatting string as $ price, e.g. 12345.45 converted to $12,345.45?

回答1:

Assuming you are using Cocoa (or just Foundation), you can use NSNumberFormatter and set its style to currency:

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterCurrencyStyle];
... = [formatter stringFromNumber:number];

By default it uses the locale of your system, but you can change that and lots of other properties, see the NSNumberFormatter API docs.

回答2:

Assuming the price is held in a float, you probably want +localizedStringWithFormat:.

NSString *priceString = [NSString localizedStringWithFormat:@"$ %'.2f",price];

Hmmm... Apple says they follow the IEEE standard for printf, so it should accept the ' flag, but it doesn't work on Tiger. NSNumberFormatter it is.

回答3:

You need to get rid of the ' character

So, just have this:

NSString *priceString = [NSString localizedStringWithFormat:@"$ %.2f", price];

回答4:

NSString *formatedNumbers = [NSNumberFormatter localizedStringFromNumber:myNumber numberStyle:NSNumberFormatterCurrencyStyle];