... it is a fundamental principle of testing that you must know in advance the answer each test case is supposed to produce. If you don't, you are not testing; you are experimenting.

Trying to outsmart a compiler defeats much of the purpose of using one.

Some compilers allow a check during execution that subscripts do not exceed array dimensions. This is a help, but not sufficient. First, many programmers do not use such compilers because They're not efficient. (Presumably, this means that it is vital to get the wrong answers quickly.)

Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.

The most effective debugging tool is still careful thought, coupled with judiciously placed print statements.

Mechanical rules are never a substitute for clarity of thought.

An effective way to test code is to exercise it at its natural boundaries