static void Main(string[] args)
{
#region An array of the base class type is created and initialized
// An array of the base class type is created and initialized
// with a member of each class in the hierarchy
Parent[] myArray = new Parent[3];
myArray[0] = new Parent();
myArray[1] = new Child();
myArray[2] = new GrandChild();
// Show that a method belonging to the base class is called from a child instance
// create ParentMethod() in Parent & iterate thru array calling
// this method to demonstrate that all child classes have access to it
// test ParentMethod() by doing a foreach loop
foreach (Parent element in myArray)
{
// GetType property is to get type of an element
Console.Write("{0}: ", element.GetType());
// call method for each element in array as it iterates thru the foreach
element.ParentMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate overriding a base class method by a child
foreach (Parent element in myArray)
{
// GetType property is to get type of an element
Console.Write("{0}: ", element.GetType());
// call method for each element in array as it iterates thru the foreach
element.SomeMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate a child method calling the parent's method
// create a virtual method in parent
// override in child and call the parent as part of the implementation
foreach (Parent element in myArray)
{
// GetType property is to get type of an element
Console.Write("{0}: ", element.GetType());
// call method for each element in array as it iterates thru the foreach
element.Method2();
Console.WriteLine();
}
Console.WriteLine();
#endregion
#region Demonstrate use of "as" keyword
// repeat calls to SomeMethod but using the as keyword
// element is of type object
foreach (object element in myArray)
{
// have to cast object to a parent type to use SomeMethod
// creating a new variable of type p
// as well as casting to type element
// following 2 lines are doing almost same thing
//Parent p = element as Parent; - cast is implicit bc of "as" operator
//Parent p = (Parent)element; - explcit cast
// Using the "as" is a litte more expressive
Parent p = (Parent)element;
Console.Write("{0}: ", p.GetType());
// call method for each element in array as it iterates thru the foreach
p.SomeMethod();
}
#endregion
#region Demonstrate use of "is" keyword
Console.WriteLine("\nDemo use of is");
foreach (Parent element in myArray)
{
// grandchild to child to parent order
// if you reverse the order, the child is-a parent
// and grandchild is-a parent
// because all derrived classes have an is-a relationship to parent
if (element is GrandChild)
{
Console.WriteLine("GrandChild");
}
else if (element is Child)
{
Console.WriteLine("Child");
}
else if (element is Parent)
{
Console.WriteLine("Parent");
}
}
Console.WriteLine();
#endregion
#region switch statement
Console.WriteLine("Demo switch:");
foreach (Parent element in myArray)
{
switch (element)
{
// within the case statement creating a variable
// can call within the switch statement block on that method
// for example, scope of p is only within the case Parent p block
case GrandChild gc:
Console.WriteLine("GrandChild");
break;
case Child c:
Console.WriteLine("Child");
break;
case Parent p:
Console.WriteLine("Parent");
break;
default:
Console.WriteLine("default");
break;
}
}
Console.WriteLine();
#endregion
#region Create an object of "object" type
//, but initialized of the base class type,
// then cast it to the actual type so you can call a method
object obj = new Parent();
/// make an explicit cast to see the methods that belong to Parent
/// first part of below is casting, second part after dot is calling to method
((Parent)obj).ParentMethod();
Parent p2 = new GrandChild();
((GrandChild)p2).SpecializedMethod();
#endregion
}
static void Main(string[] args)
{
//an array of the base class type is created and initialized
// with a member of each class in the hierarchy
Parent[] myArray = new Parent[3];
myArray[0] = new Parent();
myArray[1] = new Child();
myArray[2] = new GrandChild();
// Show that a method belonging to the base class is called from a child instance
//create ParentMethod() in Parent and iterate through array
// calling this method to demonstrate that all child classes have access to it
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.ParentMethod();
}
Console.WriteLine();
//-----------------------------------------------------
//Demonstrate overriding a base class method by a child
//parent-virtualMethod| child-overrideMethod
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.SomeMethod();
}
Console.WriteLine();
//--------------------------------------------------------
//Demostrate a child method calling the parent's method
//create a virtual method in parent
// override in child and call the parent as part of the implementation.
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.Method2();
Console.WriteLine();
}
Console.WriteLine();
//-------------------------------------------------------
//Demonstrate use of "as" keyword
//repeat calls to someMethod
foreach (object element in myArray)
{
//Parent p = element as Parent;
Parent p = (Parent)element;
Console.Write("{0}: ", p.GetType());
p.SomeMethod();
}
//---------------------------------------------------
//Demonstrate use of "is" keyword
Console.WriteLine("Demo use of is");
foreach (Parent element in myArray)
{
if (element is GrandChild)
{
Console.WriteLine("grandChild");
}
else if (element is Child)
{
Console.WriteLine("Child");
}
else if (element is Parent)
{
Console.WriteLine("Parent");
}
}
Console.WriteLine();
//------------------------------------------------------
//switch
Console.WriteLine("Demo Switch");
foreach (Parent element in myArray)
{
switch (element)
{
case GrandChild gc:
Console.WriteLine("GrandChild");
break;
case Child c:
Console.WriteLine("Child");
break;
case Parent p:
Console.WriteLine("Parent");
break;
default:
Console.WriteLine("default");
break;
}
}
//----------------------------------------------------
//Create an object of"object type, but initialized of the
//base class type, then cast it to the actual type so you can call a method
object obj = new Parent();
((Parent)obj).ParentMethod();
Parent p2 = new GrandChild();
((GrandChild)p2).SpecializedMethod();
}
static void Main(string[] args)
{
#region An array of the base class type is created and initialized
// with a member of each class in the hierarchy
Parent[] myArray = new Parent[3];
myArray[0] = new Parent();
myArray[1] = new Child();
myArray[2] = new GrandChild();
//Show that a method belonging to the base class is called from a child instance
// create ParentMethod() in Parent and iterrate through array
// calling this method to demonstrate that all child classes
// inherit from it
foreach (Parent element in myArray)
{
Console.WriteLine("{0}", element.GetType());
element.ParentMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate overriding a base class method by a child
// parent with virtual method
//child with overrid method
foreach (Parent element in myArray)
{
Console.WriteLine("{0}", element.GetType());
element.someMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate a child method calling the parent's method
// create a virtual method in parent
// override in child and call the parent as part of the implementation
foreach (Parent element in myArray)
{
Console.WriteLine("{0}", element.GetType());
element.Method2();
Console.WriteLine();
}
Console.WriteLine();
Console.Read();
#endregion
#region Demonstrate use of "as" keyword
// repeat call to SomeMethod
foreach (object element in myArray)
{
// casting at the same time as creating a new variable
Parent p = element as Parent;
// second thing is doing the cast operation
//Parent p = (Parent)element;
Console.WriteLine("{0}", element.GetType());
p.ParentMethod();
}
#endregion
#region Demonstrate the "is" keyword
Console.WriteLine("Demonstrate use of is");
foreach (Parent element in myArray)
{
if (element is GrandChild)
{
Console.WriteLine("GrandChild");
}
else if (element is Child)
{
Console.WriteLine("Child");
}
else if (element is Parent)
{
Console.WriteLine("Parent");
}
}
#endregion
// creating variables in a switch
#region switch
foreach (Parent element in myArray)
{
switch (element)
{
case GrandChild gc:
Console.WriteLine("GrandChild");
break;
case Child c:
Console.WriteLine("Child");
break;
case Parent p:
Console.WriteLine("Parent");
break;
default:
Console.WriteLine("default");
break;
}
}
Console.WriteLine();
#endregion
#region Create an object of "object" type, but initialized of the
//base class type, then cast it to the actual type so you can call a method
// explicit casting
object obj = new Parent();
((Parent)obj).ParentMethod();
Parent p2 = new GrandChild();
((GrandChild)p2).SpecializedMethod;
#endregion
Console.ReadLine();
}
static void Main(string[] args)
{
#region array of the base class type is created and initialized
//with a member of each class in the hierarchy
Parent[] myArray = new Parent[3];
myArray[0] = new Parent();
myArray[1] = new Child();
myArray[2] = new GrandChild();
//show that a method belonging to the base class is called from the
//child instance
//create parentMethod() in parent and iterate through array
//calling this method to demonstrate that all child classes
//have access to it.
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.ParentMethod();
}
Console.WriteLine();
#endregion
#region demonstrate overriding a base class method by a child
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.SomeMethod();
}
Console.WriteLine();
#endregion
#region demonstrate a child method calling the parent's method
//create a virtual method in parent
//override in child and call the parent as part of the
//implementation
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.Method2();
Console.WriteLine();
}
Console.WriteLine();
#endregion
#region Demonstrate use of "as" keyword
//repeat calls to SomeMethod
foreach (object element in myArray)
{
Parent p = element as Parent;
//Parent p = (Parent)element;
Console.Write("{0}: ", p.GetType());
p.SomeMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate use of "is" keyword
Console.WriteLine("Demo use of is");
foreach (Parent element in myArray)
{
if (element is GrandChild)
{
Console.WriteLine("GrandChhild");
}
else if (element is Child)
{
Console.WriteLine("Child");
}
else if (element is Parent)
{
Console.WriteLine("Parent");
}
}
Console.WriteLine();
#endregion
#region switch
Console.WriteLine("Demo switch");
foreach (Parent element in myArray)
{
switch (element)
{
case GrandChild gc:
Console.WriteLine("GrandChild");
break;
case Child c:
Console.WriteLine("Child");
break;
case Parent p:
Console.WriteLine("Parent");
break;
default:
Console.WriteLine("default");
break;
}
}
Console.WriteLine();
#endregion
#region object of object type initialized to base class type
object obj = new Parent();
((Parent)obj).ParentMethod();
Parent p2 = new GrandChild();
((GrandChild)p2).SpecializedMethod();
#endregion
}
static void Main(string[] args)
{
#region An array of the base class type is created and initialized
// An array of the base class type is created and initialized with
// a member of each class in the hierarchy
Parent[] myArray = new Parent[3];
myArray[0] = new Parent();
myArray[1] = new Child();
myArray[2] = new GrandChild();
// Show that a method belonging to the base class is called
// from a child instance
// create ParentMethod() in Parent and iterate through array
// calling this method to demostrate that all child classes
// have access to it
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.ParentMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate overriding a base class method by a child
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.SomeMethod();
}
Console.WriteLine();
#endregion
#region Demonstrate a child method calling the parent's method
// create a virtual method kn parent
// override in child and call the parent as part of the
// implementation
foreach (Parent element in myArray)
{
Console.Write("{0}: ", element.GetType());
element.Method2();
Console.WriteLine();
}
Console.WriteLine();
#endregion
#region Demonstrate use of "as" keyword
// repeat calls to SomeMethod
foreach (object element in myArray)
{
// casting
Parent p = element as Parent;
// explict casting
// Parent p = (Parent)element;
Console.Write("{0}: ", p.GetType());
p.SomeMethod();
}
#endregion
#region Demonstrate use of "is" keyword
Console.WriteLine("Demo use of is keyword");
foreach (Parent element in myArray)
{
// if (element is GrandChild) Console.WriteLine("GrandChild";
if (element is GrandChild)
{
Console.WriteLine("GrandChild");
}
else if (element is Child)
{
Console.WriteLine("Child");
}
else if (element is Parent)
{
Console.WriteLine("Parent");
}
Console.WriteLine();
}
#endregion
Console.WriteLine();
// Demo switch
#region switch
foreach (Parent element in myArray)
{
switch (element)
{
case GrandChild gc:
Console.WriteLine("GrandChild");
break;
case Child c:
Console.WriteLine("Child");
break;
case Parent p:
Console.WriteLine("Parent");
break;
default:
Console.WriteLine("default");
break;
}
}
#endregion
#region Create an object of "object" type, but initialized of
//the base class type, then cast it to the actual type so you
//can call a method;
{
object obj = new Parent();
((Parent)obj).ParentMethod();
Parent p2 = new GrandChild();
((GrandChild)p2).SpecializedMethod();
}
#endregion
}
