What problems might the following macro bring to the application?

Question

Can the following macro bring problems?

#define sq(x) x*x

If yes, then how and why?please help.

Answer 1

While writing macros use brackets excessively. Rewrite the macro as follows

#define sq(x) ((x)*(x))

If you don't do this then you will have problems in cases where macro is used as sq(5+4)

To understand the problem do macro expansion and see.