Code Complete, 2nd Edition

Controlling the Loop

What can go wrong with a loop? Any answer would have to include incorrect or omitted loop initialization, omitted initialization of accumulators or other variables related to the loop, improper nesting, incorrect termination of the loop, forgetting to increment a loop variable or incrementing the variable incorrectly, and indexing an array element from a loop index incorrectly.

You can forestall these problems by observing two practices. First, minimize the number of factors that affect the loop. Simplify! Simplify! Simplify! Second, treat the inside of the loop as if it were a routine—keep as much of the control as possible ...