• Functions method return values 
• Procedures do not

Methods which do not return any value 

• Called for their effect
• Often to change the value of the instance variables
• Such methods (other than Constructors) must be declared to have a return type of void 

public void MoveTo(double x, double y)

{

     this.x = x;

     this.y = y;

}

Note MoveTo() void methods returns no result hence no return statement 

Explain in details : 

public void MoveTo(double x, double y)

{

     this.x = x;

     this.y = y;

}

public void MoveTo(double x, double y) 

• Parameters x and y are called formal parameters or formal arguments of MoveTo

It is possible to have variables and methods that belong to the class rather than to its instance

• Class variables shared between all instances
• Class methods invoked on the class itself , rather than  specific instance

A class variable or method is declared with the keyword static 

// declaration of Sqrt in the class Math:

public static double Sqrt(double d); 

This can be invoked by

double sq_x = Math.Sqrt(9.6754) 

Using constructors , it when a class or struct is created , it is refer as constructor , usually initialize the data members of the new object. example :

public mySampleClass()

{

  // this is the constructor method see the differents !

}

mySampleClass obj = new mySampleClass()
// At this time the code in the constructor will // be executed

its when you have the same constructor name example mySampleCalss() repeated more than once  example would be :

public class mySampleClass
{
    public mySampleClass()
    {
        // This is the no parameter constructor method.         // First Constructor     }

    public mySampleClass(int Age)
    {
        // This is the constructor with one parameter.         // Second Constructor  
    }

    public mySampleClass(int Age, string Name)
    {
        // This is the constructor with two parameters.         // Third Constructor     }

    // rest of the class members goes here. }

In C# types describle values.

Types in  C# are divided into value types and reference types.

Value type describle values that are completely self contained 

Reference types: however store a reference to a value rather than the actual value. 

Just as a reminder, overloading is what happens when you have two methods with the same name but different signatures.

• overloading should be used for convenience

A Class is a template from which software objects are made. Example button control , double click on button and you enter the button class are

public void button_click(boolen T)

{

 this would be seen as a class

}

static makes a member of a class part of a class rather than part of an instance of the class. This means that you don’t need to create an instance of a class to make use of a static member