I want to know the detail description on the size of a class.
I want to know if there is only data members & member function without any virtual keyword then why the class size depends only on data members.
For an eg:

```
class A {
    int a;
public:
    int display() { 
    cout << "A=" << a << endl;
   }
};

```

When I check the `sizeof(A)` i found that it is 4 byte. Why it is so? Why member function has no effect on the size of class A?

Thanks