C ++What is the Size of an Empty Class Object in C?

The following is an example of finding the size of an object of an empty class.

Example

#include <bits/stdc++.h>
using namespace std;
class p1　{
　　　public:
　　　void first() {
　　　　　　cout << "\nThe parent class p1　function is called.";
　　　}
};
class p2
{ };
int main() {
　　　cout << "The size of non-empty class p1　= " << sizeof(p1);
　　　cout << "\nThe size of empty class p2　= " << sizeof(p2);
　　　p2　p;
　　　cout << "\nThe size of object of empty class p2　= " << sizeof(p);
　　　p1　o;
　　　cout << "\nThe size of object of non-empty class p1　= " << sizeof(o);
　　　return 0;
}

Output Result

The size of non-empty class p1　=　1
The size of empty class p2　=　1
The size of object of empty class p2　=　1
The size of object of non-empty class p1　=　1

In the above program, an empty class p is created2.

class p2
{ };

The size of class and object is printed as follows:

cout << "The size of non-empty class p1　: " << sizeof(p1);
cout << "\nThe size of empty class p2　: " << sizeof(p2);
p2　p;
cout << "\nThe size of object of empty class : " << sizeof(p);
p1　o;
cout << "\nThe size of object of non-empty class p1　: " << sizeof(o);