Is declaration of variables expensive?

Question

While coding in C, I came across the below situation.

int function ()
{
  if (!somecondition) return false;

  internalStructure  *str1;
  internalStructure *str         


        

Answer 1

Yes, it can cost clarity. If there is a case where the function must do nothing at all on some condition, (as when finding the global false, in your case), then placing the check at the top, where you show it above, is surely easier to understand - something that is essential while debugging and/or documenting.