Do You Know Size Of Empty Class and Reason?

Size of empty class is always 1 byte.

Reason is, in order to differentiate one object to another object, the size of empty class is always 1 byte.

See the below c++ code snippet. Here there are three object created, each object size is 1. Their address is +1 byte for each object.

#include
using namespace std;

// Empty class declaration
class Student
{
};

int main() {
    // Object creation
    Student s1,s2,s3;

    // Getting sizeof the object
    cout << "Size of empty class Student for object s1 " << sizeof(s1) << endl;
    cout << "Size of empty class Student for object s2 " << sizeof(s2) << endl;
    cout << "Size of empty class Student for object s3 " << sizeof(s3) << endl;

    // Getting address of the object
    cout << "Address of object s1 " << &s1 << endl;
    cout << "Address of object s2 " << &s2 << endl;
    cout << "Address of object s3 " << &s3 << endl;
    
    return 0;
}

output
Size of empty class Student for object s1 1
Size of empty class Student for object s2 1
Size of empty class Student for object s3 1

Address of object s1 0x7ffc4fb8572d
Address of object s2 0x7ffc4fb8572e
Address of object s3 0x7ffc4fb8572f