[Warning] comparison between pointer and integer

[rkooij]

Hi guys, quick one, think it should be easy for you c cracks.

This line:

      else if((lines%3)!=NULL)

Results in this warning:
[Warning] comparison between pointer and integer

lines is defined as an integer and is 3 in this case.

What need I do to avoid getting this warning please?

Thanks in advance,

René

[ZuK]

e.g.

      else if( lines%3 )

Kurt

[rkooij]

e.g.

      else if( lines%3 )

Kurt

Ah! NULL != 0 right?

Damn, knew it was simple

Thanks

[Prelude]

>What need I do to avoid getting this warning please?
Simple, don't use NULL except in pointer context. If you want to compare against 0 then use 0. If you want to compare against '\0' then use '\0'. If you want to test for a null pointer then use NULL.

The reason you're getting the error is because NULL is defined as 0 with a pointer type, most likely like this:

#define NULL ((void*)0)

The result of a boolean expression, lines%3, has an integer type.

[rkooij]

Good explanation, thanks a lot.
*feels dumb* though

[Prelude]

>*feels dumb* though
If you knew the confusion that NULL has caused in the past then you would feel very smart about understanding the problem so quickly.