C Preprocessor Instructions (SQR-Funktion)

Question

Want to know how "11" is the answer of this c preprocessor instruction:

#define SQR(x) x*x

int main()
{
    SQR(2+3);
}

1. Because macro expansion is dumb textual replacement. 2. I asked does it print?, you said yes and I seriously doubt. Possibly it (main) returns 11. Reading macros from a C book should help. — Mohit Jain, Feb 28 '16 at 18:58

score 0 · Answer 1 · answered Feb 28 '16 at 14:26

0

Try expanding the macro manually.

It will be 2+3*2+3 and this is evaluated as 11.

answered Feb 28 '16 at 14:26

MikeCAT

1

Why downvoted your answer? it is correct. Maybe a little ... minimal, but correct. Better add that this is the reason why is always better to add parenthesis around parameters. Try this: `#define SQR(x) ((x)*(x))` – Frankie_C Feb 28 '16 at 14:33
im just wondering why it does 2+3*2+3 – vamosfener Feb 28 '16 at 14:43
@vamos Order of operations: multiplication first, then addition from left to right. 3 * 2 is 6, plus 2 is 8, plus 3 is 11. – Cody Gray - on strike Feb 28 '16 at 14:54

1 Answers1