Operator OverLoading in console apps

class ClsComplex
{
int R, I;
public ClsComplex(int R, int I)
{
this.R = R;
this.I = I;
Console.WriteLine("{0} + {1}i", R, I);
}
public static ClsComplex operator +(ClsComplex Num1, ClsComplex Num2)
{
ClsComplex Num3 = new ClsComplex(Num1.R + Num2.R, Num1.I + Num2.I);
return Num3;
}
}
class ClsOpOverLoad
{
static void Main(string[] args)
{
Console.Write("C1= ");
ClsComplex C1 = new ClsComplex(4, 5);
Console.Write("C2= ");
ClsComplex C2 = new ClsComplex(8, 2);
Console.Write("C3= ");
ClsComplex C3 = C1 + C2;
Console.Read();
}
}

Method OverLoading in console apps

class mOverLoading
{
int x=10;
public void show()
{
Console.WriteLine("default constructor");
Console.WriteLine(x + this.x);
}
public void show(int x)
{
Console.WriteLine("Parameterized constructors");
Console.WriteLine(x+" "+this.x);
}
public void show(string s, int x)
{
Console.WriteLine("Parameterized constructor");
Console.WriteLine(s + " " + x);
}
public static void Main()
{
mOverLoading mol = new mOverLoading();
mol.show();
mol.show(123);
mol.show("satya", 456);
Console.ReadLine();
}
}

Constructor OverLoading in Console apps

class CACOverLoading
{
int x;
public CACOverLoading()
{
Console.WriteLine("Default constructor");
x = 123;
}
public CACOverLoading(int x)
{
Console.WriteLine("Parameterized constructor");
Console.WriteLine(x);
this.x = 789;
}
public void display()
{
Console.WriteLine(x);
}
public static void Main()
{
CACOverLoading col = new CACOverLoading();
col.display();
CACOverLoading col1 = new CACOverLoading(456);
col1.display();
Console.ReadLine();
}
}

Virtual class overriding

class Virtual
{
public virtual void add(int a, int b)
{
Console.WriteLine(a + b);
}
}
class overridevirtual:Virtual
{
public override void add(int a, int b)
{
Console.WriteLine(a);
}
public static void Main()
{
Virtual vir = new Virtual();
vir.add(1,2);
Console.ReadLine();
}
}

Abstract overriding in console apps

abstract class Abstract {

public abstract void mul(int x);
public void add(int x, int y)
{
Console.WriteLine("add is: "+(x + y));
}
}
class overrideabstract : Abstract
{
public override void mul(int a)
{
Console.WriteLine("mul is: "+a*a);
}
public static void Main()
{
overrideabstract ovra = new overrideabstract();
ovra.add(4, 5);
ovra.mul(3);
Console.ReadLine();
}
}

Note: An abstract class can implement from another abstract class. and a class can implement only one abstract class at a time.