What is the purpose of using !! for Pointers in C Conditions?

Asked Oct 13 '15 at 13:47

Active Oct 13 '15 at 13:49

Viewed 112 times

I have seen code which uses a double not (!!) for checking a pointer.But I am not finding an advantage of using !! in the condition check.Can some one shed some light on the purpose and advantage of using it.

int *Ptr;
/* ... */
if(!!Ptr)
{
  /* ... */
}

edited Oct 13 '15 at 13:49

Hcorg

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asked Oct 13 '15 at 13:47

achoora

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guarantees that conditional will evaluate either as 0 or 1. – 101010 Oct 13 '15 at 13:50
see http://stackoverflow.com/questions/248693/double-negation-in-c-code – jha-G Oct 13 '15 at 13:51
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Tldr it's unnecessary here, and a compiler like GCC optimizes everything away – deviantfan Oct 13 '15 at 13:53
It's a much dumber way of writing `if(Ptr != NULL)`. – Lundin Oct 13 '15 at 15:18

What is the purpose of using !! for Pointers in C Conditions?

0 Answers0