sizeof for a class

coderzone · #1 06-04-2007, 11:21 AM

Code:

Class A
{
  int a;
  float b;
};

Now what will be the value of sizeof(A);

tiger12506 · #2 06-05-2007, 08:48 PM

Check it out for yourself.
"class" is not a keyword in C. A struct is basically the same thing. I do know that "class" in c++ is just a "struct" with a default of private...

Code:

#include <stdio.h>

struct A {
  int a;
  float b;
};

int main() {
  printf("sizeof(int) = %d\n",sizeof(int));
  printf("sizeof(float) = %d\n",sizeof(float));
  printf("sizeof(struct A) = %d\n",sizeof(struct A));
}

I get:

sizeof(int) = 4
sizeof(float) = 4
sizeof(struct A) = 8

But those values could be different on different platforms. The trick is that usually the size of the items in the struct add up to the size of the struct itself

coderzone · #3 06-05-2007, 10:29 PM

I just wanted to post something else. Something like

Code:

struct A
{
  int a;
  double b;
};

Now check what will be the size of and you will see the difference and why I have put it here.