I've seen a lot of question on the internet about this topic.
Here it is my preferred solution:
NSInteger theNumber = 56; // setup here your value….
NSMutableString *str = [NSMutableString string];
for(NSInteger numberCopy = theNumber; numberCopy > 0; numberCopy >>= 1)
{
// Prepend "0" or "1", depending on the bit
[str insertString:((numberCopy & 1) ? @"1" : @"0") atIndex:0];
}
NSLog(@"Binary version: %@", str);
Gg1