Classes_vs_Structs.cs

using System;

/* //Differences between Classes and Stucts//
 * 
 * A Struct is a VALUE TYPE -- it is stored on the stack
 * 
 * A Class is a REFERENCE TYPE -- it is stored on the heap
 * 
 * VALUE TYPES hold their value in memory where they are declared
 * REFERENCE TYPES hold a reference to an object in memory
 * 
 * VALUE TYPES are destroyed immediately after the scope is lost
 * REFERENCE TYPES -- only the reference variable is destroyed after scope is lost
 *  + The object is later destroyed by garbage collection
 *  
 * When you copy a struct into another struct, the new copy of that strut gets created and
 * modifications on one struct will not affect the values contained by the other struct
 * 
 * When you copy a class into another class, you only get a copy of the reference variable.
 * Both reference values point to the same object on the heap.
 * In other words, operations on one variable will affect the values contained by the other reference variable
 *  
 */

public class MyName
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

public class Program
{
    public static void Main()
    {
        //VALUE TYPES - operations on the value of 'y' WILL NOT affect the value of 'x'
        int x = 1;
        int y = x;
        y = y + 1; 

        Console.WriteLine("x = {0}", x);
        Console.WriteLine("y = {0}", y);

        
        //REFERENCE TYPE -- operations on the value of 'a' WILL affect the value of 'b'
        MyName a = new MyName();
        a.FirstName = "Derrik";
        a.LastName = "Nasca";

        MyName b = a; //This will create another object reference variable to the SAME OBJECT on the heap
        b.FirstName = "Anthony"; //remember, b is NOT a new object, it is simply a reference to the object reference variable 'a'
                                 //therefor, b.FirstName will do exactly the same thing as a.FirstName

        //Important Note: While objects reside on the Heap, the object reference variables exist on the stack

        Console.WriteLine(a.FirstName);
        Console.WriteLine(b.LastName);

        Console.ReadKey();
    }
}

/* //Some final notes about Structs//
 * 
 * Structs cannot have destructors
 * 
 * Structs can't inheret from another class, but can inherit from an interface
 * 
 * Structs cannot have explicit parameter-less constructors
 * 
 * Structs are sealed types
 * 
 */