What happens when we try to compile the class definition in following code snippet?

class Birds {};
class Peacock : protected Birds {};

#include<iostream.h> 
class Addition
{
    int x; 
    public: 
    Addition()
    {
        x = 0;
    }       
    Addition(int xx)
    {
        x = xx;
    }
    Addition operator + (int xx = 0)
    {
        Addition objTemp; 
        objTemp.x = x + xx; 
        return(objTemp);
    }
    void Display(void)
    {
        cout<< x << endl;
    }
};
int main()
{
    Addition objA(15), objB;
    objB = objA + 5;
    objB.Display();
    return 0; 
}

#include<iostream.h> 
class CuriousTabBase
{
    int x, y; 
    public:
    CuriousTabBase(int xx = 10, int yy = 10)
    {
        x = xx;
        y = yy;
    }
    void Show()
    {
        cout<< x * y << endl;
    }
};
class CuriousTabDerived
{
    private:
        CuriousTabBase objBase; 
    public:
    CuriousTabDerived(int xx, int yy) : objBase(xx, yy)
    {
        objBase.Show();
    }
};
int main()
{
    CuriousTabDerived objDev(10, 20);
    return 0; 
}

#include<iostream.h> 
class Point
{
    int x, y; 
    public:
    Point(int xx = 10, int yy = 20)
    {
        x = xx;
        y = yy; 
    }
    Point operator + (Point objPoint)
    {
        Point objTmp;
        objTmp.x = objPoint.x + this->x; 
        objTmp.y = objPoint.y + this->y;
        return objTmp;
    }
    void Display(void)
    {
        cout<< x << " " << y;
    }
};
int main()
{
    Point objP1;
    Point objP2(1, 2);
    Point objP3 = objP1 + objP2;
    objP3.Display(); 
    return 0; 
}

#include<iostream.h>
#include<string.h> 
class CuriousTab
{
    public:
    void GetData(char *s, int x, int y )
    {
        int i = 0;
        for (i = x-1; y>0; i++)
        {
            cout<< s[i];
            y--; 
        } 
    }
}; 
int main()
{
    CuriousTab objCuriousTab;
    objCuriousTab.GetData((char*)"Welcome!", 1, 3);
    return 0; 
}

#include<iostream.h> 
int i, j; 
class CuriousTab
{
    public:
    CuriousTab(int x = 0, int y = 0)
    {
        i = x; 
        j = x; 
        Display();
    }
    void Display()
    {
        cout<< j <<" ";
    } 
}; 
int main()
{
    CuriousTab objCuriousTab(10, 20); 
    int &s = i; 
    int &z = j; 
    i++;
    cout<< s-- << " " << ++z; 
    return 0; 
}

#include<iostream.h> 
class Base
{
    public:
    int S, A, M; 
    Base(int x, int y)
    {
        S = y - y;
        A = x + x; 
        M = x * x;
    }
    Base(int, int y = 'A', int z = 'B')
    {
        S = y;
        A = y + 1 - 1; 
        M = z - 1;
    }
    void Display(void)
    {
        cout<< S << " " << A << " " << M << endl;
    }
};
class Derived : public Base
{
    int x, y, z; 
    public:
    Derived(int xx = 65, int yy = 66, int zz = 67): Base(x)
    {
        x = xx; 
        y = yy;
        z = zz;
    }
    void Display(int n)
    {
        if(n)
            Base::Display(); 
        else
            cout<< x << " " << y << " " << z << endl; 
    }
};
int main()
{
    Derived objDev; 
    objDev.Display(-1); 
    return 0;
}

#include<iostream.h>
int CuriousTabFunction(int a, int b = 3, int c = 3)
{
    cout<< ++a * ++b * --c ; 
    return 0;
}
int main()
{
    CuriousTabFunction(5, 0, 0); 
    return 0;
}

#include<iostream.h> 
class CuriousTab
{
    int x; 
    float y; 
    public:
    void Function()
    {
        x = 4; 
        y = 2.50; delete this;
    }
    void Display()
    {
        cout<< x << " " << y;
    } 
}; 
int main()
{
    CuriousTab *pCuriousTab = new CuriousTab();
    pCuriousTab->Function(); 
    pCuriousTab->Function(); 
    pCuriousTab->Display(); 
    return 0; 
}