Why does sizeof(MACRO) give an output of 4 bytes when MACRO does not hold any memory location?

Question

Below is the small program:

#include <stdio.h>
#define max 'A'

int main()
{
    char a;
    printf("max[%d] sizeof[max][%ld]\n", max, sizeof(max));
    a = max;
    printf("a[%d] sizeof[a][%ld]\n", a, sizeof(a));
    return 0;
}

And the output of the program is:

max[65] sizeof[max][4]
a[65] sizeof[a][1]

Can anyone help me to understand why the sizeof(max) is 4 bytes?

Answer 1

sizeof(max) is replaced by the preprocessor with sizeof('A'). sizeof('A') is the same as sizeof(int), and the latter is 4 on your platform.

For the avoidance of doubt, 'A' is an int constant in C, not a char. (Note that in C++ 'A' is a char literal, and sizeof(char) is fixed at 1 by the standard.)