Question

When I wish to check if a value is 0 in C, how is it idiomatically done?

• if (!num)
• if (num == 0)

Answer 1

While this is a matter of taste, I find it pretty much depends on intention. If the value is to be used as a boolean, ! is alright. If the value is counting something the equality makes more sense.

if (!isVisible) {...}
if (isVisible == 0) {...} // Intention not as clear as line above.

if (numberOfItems == 0) {...}
if (!numberOfItems) {...} // Intention not as clear as line above.