Program to illustrates Container Classes with constructors

#include <iostream.h>
#include <string.h>
/*----------------------Class Interfaces-------------------------*/
class A
{
        int x;
    public :
        A(int);                    // Constructor
        void display();
};
class B
{
        char w[10];
        int y;
    public :
        B(char*,int);            // Constructor
        void display();
};
class C                        // container class
{
        A obj1;                    // object of class A
        B obj2;                    // object of class B
        int z;
    public :
        C(int,int,int,char*);
        void display();
};
/*----------------------Class Implementations---------------------*/
// member function definitions for 'A'
A::A(int a)
{
    x = a;
}
void A::display()
{
    cout << "x = "<< x << "\n";
}
// member function definitions for 'B'
B::B(char* a, int b)
{
    strcpy(w, a);
    y = b;
}
void B::display()
{
    cout << "w = " << w << "\n";
    cout << "y = " << y << "\n";
}
// member function definitions for 'C'
C::C(int a, int b, int c, char* d): obj1(a), obj2(d,c)
{
    z = b;
}
void C::display()
{
    obj1.display();
    obj2.display();
    cout << "z = " << z << "\n";
}
/*----------------------Class definitions ends here---------------*/
void main(void)
{
    C c(10,20,30,"God");
    c.display();
}