Should I use `!IsGood` or `IsGood == false`?

Question

I keep seeing code that does checks like this

if (IsGood == false)
{
   DoSomething();
}

or this

if (IsGood == true)
{
   D         


        

Answer 1

It's possible (although unlikely, at least I hope) that in C code TRUE and FALSE are #defined to things other than 1 and 0. For example, a programmer might have decided to use 0 as "true" and -1 as "false" in a particular API. The same is true of legacy C++ code, since "true" and "false" were not always C++ keywords, particularly back in the day before there was an ANSI standard.

It's also worth pointing out that some languages--particularly script-y ones like Perl, JavaScript, and PHP--can have funny interpretations of what values count as true and what values count as false. It's possible (although, again, unlikely on hopes) that "foo == false" means something subtly different from "!foo". This question is tagged "language agnostic", and a language can define the == operator to not work in ways compatible with the ! operator.