When we use sizeof operator on object of that class which do not have any data members. Then what would be the output?

Question

When we use sizeof operator on object of that class which do not have any data members. Then what would be the output? Why this always output 1??

class Abhi
{
public :
int sum (int, int);
int avg (int);
};
int Abhi:: sum(int a, int b)
{
float c;
c=a+b;
return 0;
}

int main()
{
Abhi abh;
int c;
c= sizeof(abh);
cout<<c;
}

Answer 1

According to the standard, each instance of a class must have a unique address. This is usually implemented by giving an "empty" class (no data members) a minimum size, as if there is a dummy char inside. This is why sizeof gives 1 and not 0.