Remove negative symbol (-) from NSDecimalNumber gives me an error

Question

I have an array with NSDecimalNumbers inside. I will do a check to see if that number is a negative number. If it is, I want to remove the negative sign (-). Here is my code:

NSString *amount = [myArray objectAtInde:2]; // Is a NSDecimalNumber with value of: -397.67

    if ([amount doubleValue] < 0) {
        amount = [amount stringByReplacingOccurrencesOfString:@"-" withString:@"- $"];
    }

When I do that, I get the following error:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSDecimalNumber stringByReplacingOccurrencesOfString:withString:]: unrecognized selector sent to instance 0x7fcaf94eff80'

Answer 1

Try this,

NSDecimalNumber *amountNumber = [myArray objectAtIndex:2]; // Is a NSDecimalNumber with value of: -397.67

NSString *stringWithDollarSymbol = [self addDollarSymoblForNumber:amountNumber];

You can assign the stringWithDollarSymbol to label

- (NSString *)addDollarSymoblForNumber:(NSDecimalNumber *)decimalNum
{
    NSString *modifiedString = @"";
    if (decimalNum) {
        NSString *numberInStringForm = [decimalNum stringValue];
            if ([decimalNum doubleValue] < 0) { //adds dollor symbol for negative numbers
            modifiedString = [numberInStringForm stringByReplacingOccurrencesOfString:@"-" withString:@"- $"];
        }
        else //adds dollor symbol for positive numbers
        {
            modifiedString = [NSString stringWithFormat:@"$ %@",modifiedString];
        }
    }
    return modifiedString;
}

EDIT

More Better Approach using NSNumberFormatter:

- (NSString *)formatNumberBasedOnCurrentLocale:(NSDecimalNumber *)number
{
    NSNumberFormatter *formatter = [[NSNumberFormatter  alloc] init];
    [formatter setLocale:[NSLocale currentLocale]];
    [formatter setNumberStyle:NSNumberFormatterCurrencyStyle];
    NSString *result = [formatter stringFromNumber:number];
    if (result.length >0) {
        return result;
    }
    return nil;
}