Comments on: Programming Style: Two Booleans, Three Possible Cases http://www.jamiephelps.com/all/programming-style-two-booleans-three-possible-cases Proving the sunshine since 1980. Sat, 06 Feb 2010 01:07:03 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: David A Teare http://www.jamiephelps.com/all/programming-style-two-booleans-three-possible-cases/comment-page-1#comment-119 David A Teare Fri, 26 Sep 2008 23:55:04 +0000 http://www.jamiephelps.com/?p=97#comment-119 <p>If foo && bar are both false, your first example will execute the else clause, which you comment is "do bar-only stuff", which is false.</p> <p>I think you needed an extra 'else if' clause.</p> If foo && bar are both false, your first example will execute the else clause, which you comment is “do bar-only stuff”, which is false.

I think you needed an extra ‘else if’ clause.

]]> By: Mark Hughes http://www.jamiephelps.com/all/programming-style-two-booleans-three-possible-cases/comment-page-1#comment-117 Mark Hughes Thu, 25 Sep 2008 14:27:30 +0000 http://www.jamiephelps.com/?p=97#comment-117 <p>If foo and bar are set by logically related tests, there's likely some common value you can use for them both. Lacking that common value, I'd do this:</p> <p>NSInteger choice = (foo ? 1 : 0) | (bar ? 2 : 0); switch (choice) { case 0: // nothing break; case 1: // foo break; case 2: // bar break; case 3: // foo and bar break; default: NSAssert1(NO, @"Invalid choice %d", choice); }</p> <p>This makes it instantly clear that I've covered all possible choices; I have to stop and think about the nested if statements every time I come by that code.</p> If foo and bar are set by logically related tests, there’s likely some common value you can use for them both. Lacking that common value, I’d do this:

NSInteger choice = (foo ? 1 : 0) | (bar ? 2 : 0); switch (choice) { case 0: // nothing break; case 1: // foo break; case 2: // bar break; case 3: // foo and bar break; default: NSAssert1(NO, @”Invalid choice %d”, choice); }

This makes it instantly clear that I’ve covered all possible choices; I have to stop and think about the nested if statements every time I come by that code.

]]>