NSNumberFormatter and 'th' 'st' 'nd' 'rd' (ordinal) number endings

This does the trick in one method (for English). Thanks nickf https://stackoverflow.com/a/69284/1208690 for original code in PHP, I just adapted it to objective C:-

-(NSString *) addSuffixToNumber:(int) number
{
    NSString *suffix;
    int ones = number % 10;
    int tens = (number/10) % 10;

    if (tens ==1) {
        suffix = @"th";
    } else if (ones ==1){
        suffix = @"st";
    } else if (ones ==2){
        suffix = @"nd";
    } else if (ones ==3){
        suffix = @"rd";
    } else {
        suffix = @"th";
    }

    NSString * completeAsString = [NSString stringWithFormat:@"%d%@", number, suffix];
    return completeAsString;
}

As of iOS 9

Swift 4

private var ordinalFormatter: NumberFormatter = {
    let formatter = NumberFormatter()
    formatter.numberStyle = .ordinal
    return formatter
}()

extension Int {
    var ordinal: String? {
        return ordinalFormatter.string(from: NSNumber(value: self))
    }
}

It's probably best to have the formatter outside the extension...

The correct way to do this from iOS 9 onwards, is:

NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
numberFormatter.numberStyle = NSNumberFormatterOrdinalStyle;

NSLog(@"%@", [numberFormatter stringFromNumber:@(1)]); // 1st
NSLog(@"%@", [numberFormatter stringFromNumber:@(2)]); // 2nd
NSLog(@"%@", [numberFormatter stringFromNumber:@(3)]); // 3rd, etc.

Alternatively:

NSLog(@"%@", [NSString localizedStringFromNumber:@(1)
                                     numberStyle:NSNumberFormatterOrdinalStyle]); // 1st