Question

When the follow code is run it goes inside the for loop and run NSLog. Why does this happen?

NSString *aString = nil;

for (int i=0; i<([aString length]-2); i++) {
   NSLog(@"Inside loop.");
}

As i figure [aString length]-2 results in -2 and that’s less then 0?

Answer 1

To be more precise, -[NSString length] returns an unsigned integer, so subtracting two from zero (remember, calling any method on nil gives you zero) doesn’t give you -2, it gives you a very, very large number. Cast it to an int (or an NSInteger) to get the results you want.