I'm with Athanasius on this one. There might be a clever way to make it work in a single loop. But I would prefer to go the wordier route for the sake of clearer documentation. The time spent in writing and later reading/modifying the code is significant compared to the time it will take to execute. Be good to yourself (and any future maintainers). Treat cases separately any time they would make your if clauses start to look like spaghetti.