Detecting if NSNumber is between 0 and 255

Question

I am trying to detect whether a NSNumber is between 0 and 255 or not. Whenever I run the app, I receive the alert view that my number is greater than 255, even when it is not. I do not have this problem with 0.

if (redValue < 0) {

    NSLog(@"Red value is less than 0");

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Your number must be greater than 0." message:nil delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    [alert show];
    [alert release];


} else if (redValue > 255) {

    NSLog(@"Red value is greater than 255");

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Your number must be less than 255." message:nil delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    [alert show];
    [alert release];

}

Additionally, I receive this warning on the "else if (redValue > 255)" line: Ordered comparison between pointed and integer ('NSNumber *' and 'int'), So I'm assuming I have to convert this NSNumber to an integer?

Answer 1

Should be:

if([redValue intValue] < 0) {
...

if([redValue intValue] > 255) {
...

Assuming it is an int. If it isn't go to the NSNumber Class Reference look under "Accessing Numeric Values" and replace intValue with the appropriate thing.

Answer 2

use intValue to get the number as an int:

[redValue intValue]

Answer 3

try this

[redValue intValue] > 255