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

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

Add below method in your source file
// multiplies number with -1 if it is less than zero else returns the same
- (NSDecimalNumber *)abs:(NSDecimalNumber *)num
{
if ([num compare:[NSDecimalNumber zero]] == NSOrderedAscending)
{
// Number is negative. Multiply by -1
NSDecimalNumber * negativeOne = [NSDecimalNumber decimalNumberWithMantissa:1
exponent:0
isNegative:YES];
return [num decimalNumberByMultiplyingBy:negativeOne];
}
else
{
return num;
}
}
And convert instance of NSDecimalNumbers to abs value without doing any type conversion as-
NSDecimalNumbers *number = [myArray objectAtInde:2];
number = [number abs:number];
the number returned will contain abs value in NSDecimalNumbers format.

Answer 2

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;
}

Answer 3

Please add line,
if ([amount doubleValue] < 0) {
amount=[NSString stringWithFormat:#"%#",[myArray objectAtIndex:2]];//add line
amount = [amount stringByReplacingOccurrencesOfString:#"-" withString:#""];
}
it may be work for you,

Answer 4

I just used your code & it's working fine at my end.
Tried below thing,
NSString *amount = #"-397.67";//[myArray objectAtInde:2]; // Is a NSDecimalNumber with value of: -397.67
if ([amount doubleValue] < 0) {
amount = [amount stringByReplacingOccurrencesOfString:#"-" withString:#""];
}
Try it at your end.
If nothing will work then multiply your negative float value with -1 & you will get positive number. If that is your requirement.

Answer 5

Your [myArray objectAtInde:2] is a NSDecimalNumber rather than NSString, try this:
NSDecimalNumber *amountNumber = [myArray objectAtInde:2];
NSString *amount = [NSString stringWithFormat:#"%#", amountNumber];

Answer 6

Maybe you should try this one:
NSString *amount = #(ABS([myArray[2] doubleValue])).stringValue ; // Is a NSDecimalNumber with value of: -397.67

Answer 7

If your intention is to rescue from the negative then just simply convert the value into an absolute value.
NSString *amount = [myArray objectAtIndex:2]; // Is a NSDecimalNumber with value of: -397.67
NSLog(#"The value is : %#",[NSString stringWithFormat:#"%.2f", fabs([amount doubleValue])]);
The value is: 397.67