Why should I use asserts?

Question

I never got the idea of asserts -- why should you ever use them?

I mean, let\'s say I were a formula driver and all the asserts were things like security belt, helm

Answer 1

From Code Complete 2: "Use error-handling for conditions you expect to occur; use assertions for conditions that should never occur."

A commonly-cited example is checking for zero in the denominator before a division.

You're expected to strip the assertions out of production code. They are in there during development to help you catch mistakes.

Unit tests are not a replacement for assertions.