what's the mechanism of sizeof() in C/C++?

Question

It seems sizeof is not a real function?

for example, if you write like this:

int i=0;
printf(\"%d\\n\", sizeof(++i));
printf(\"%d\\n\", i);
         


        

Answer 1

sizeof() returns the size in bytes of whatever you pass as an argument to it. In a 32-bit architecture sizeof(int) would return 4, while sizeof(char) would return 1.