C Programming Macros multiplication [duplicate]

Question

Possible Duplicate:
C Macros and use of arguments in parentheses

I found this macro question to be very interesting.

If this following code is defined as a Macro

#define MULT(x, y) x * y

And the function call is made as int z = MULT(3 + 2, 4 + 2);. The Desired output is 3+2=5 and 4+2=6 And 5*6 to be 30.

But the returned output was 13. It takes it as 3+2*4+2. Hence according to the precedence of operators it evaluates 2*4 first.

What is the fix here? In case of smaller functions like these which one is efficient? Defining the function or using the macros?

Answer 1

Try something like:

#define MULT(x, y) ((x)*(y))