How can i display the number in such a format? - objective-c

Question

I am displaying a number in textfield. Which displays the number as "1234" but i want to display it as in format of "1,234" if i enter another large number which displays as "12345" but i want to display it as "12,345" if i enter 123456 which has to display as "123,456" . How do I format this number in desired format?
-(void)clickDigit:(id)sender
{
NSString * str = (NSString *)[sender currentTitle];
NSLog(#"%#",currentVal);
if([str isEqualToString:#"."]&& !([currentVal rangeOfString:#"."].location == NSNotFound) )
{
return;
}
if ([display.text isEqualToString:#"0"])
{
currentVal = str;
[display setText:currentVal];
}
else if([currentVal isEqualToString:#"0"])
{
currentVal=str;
[display setText:currentVal];
}
else
{
if ([display.text length] <= MAXLENGTH)
{
currentVal = [currentVal stringByAppendingString:str];
NSLog(#"%#",currentVal);
[display setText:currentVal];
}
currentVal=display.text;
}
}
This is the code i am using to display the number in textfield.
EDIT: I Changed my code into the following but still don't get the number correctly formatted:
if ([display.text length] <= MAXLENGTH) {
currentVal = [currentVal stringByAppendingString:str];
NSNumberFormatter * myNumFormatter = [[NSNumberFormatter alloc] init];
[myNumFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber *tempNum = [myNumFormatter numberFromString:currentVal];
NSLog(#"My number is %#",tempNum);
[display setText:[tempNum stringValue]];
currentVal=display.text;
}

Answer 1

You can do it like this:
int myInt = 12345;
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
formatter.numberStyle = NSNumberFormatterDecimalStyle;
NSNumber *number = [NSNumber numberWithInt:myInt];
NSLog(#"%#", [formatter stringFromNumber:number]); // 12,345
Edit
You didn't implement this correctly, the key is to obtain the string representation of the number using [formatter stringFromNumber:number], but you didn't do that. So change your code into:
currentVal = [currentVal stringByAppendingString:str];
NSNumberFormatter * myNumFormatter = [[NSNumberFormatter alloc] init];
[myNumFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber *tempNum = [myNumFormatter numberFromString:currentVal];
NSLog(#"My number is %#",tempNum);
[display setText:[myNumFormatter stringFromNumber:tempNum]]; // Change this line
currentVal=display.text;
NSLog(#"My formatted number is %#", currentVal);

Answer 2

First, read through the list of methods on the NSNumberFormatter reference page. After doing that, you'll probably realize that you need to use the -setHasThousandSeparators: method to turn on the thousand separators feature. You can also use the -setThousandSeparator: method to set a custom separator, though you probably won't need to do that.