Schedule

Schedule

Wednesday, October 22

1413991800 FLOSS Weekly
1413997200 Tech News Today
1414000800 Windows Weekly
1414008000 This Week in Google
1414018800 Tech News 2Night
1414026000 Ham Nation

Thursday, October 23

1414083600 Tech News Today
1414087200 Know How...
1414090800 Marketing Mavericks
1414096200 Coding 101
1414099800 Home Theater Geeks
1414105200 Tech News 2Night
1414107000 The Giz Wiz

Friday, October 24

1414170000 Tech News Today
1414173600 This Week in Law
1414180800 Android App Arena
1414191600 Tech News 2Night

Saturday, October 25

1414260000 The Tech Guy

Sunday, October 26

1414346400 The Tech Guy
1414360800 This Week in Tech

Monday, October 27

1414429200 Tech News Today
1414432800 Triangulation
1414438200 iPad Today
1414450800 Tech News 2Night

Tuesday, October 28

1414515600 Tech News Today
1414519200 MacBreak Weekly
1414526400 Security Now
1414533600 Before You Buy
1414537200 Tech News 2Night
1414540800 All About Android
1414549800 Padre's Corner

Wednesday, October 29

1414596600 FLOSS Weekly
1414602000 Tech News Today
1414605600 Windows Weekly
1414612800 This Week in Google
1414623600 Tech News 2Night
1414630800 Ham Nation

Thursday, October 30

1414688400 Tech News Today
1414692000 Know How...
1414695600 Marketing Mavericks
1414701000 Coding 101
1414704600 Home Theater Geeks
1414710000 Tech News 2Night
1414711800 The Giz Wiz

Friday, October 31

1414774800 Tech News Today
1414778400 This Week in Law
1414785600 Android App Arena
1414796400 Tech News 2Night

Most Recent Episodes

All About Android

A deep dive into all of Google's latest announcements around Lollipop and the new Nexus family.

Before You Buy

Leo Laporte reviews the Galaxy Note 4.

Security Now
Episode #478: Poodle Bites October 21st, 2014

Steve Gibson takes a deep dive into the "Poodle" security vulnerability.

Tech News 2Night

3-D gun printer gets prison time, Nielsen goes after web ratings

MacBreak Weekly

OS X Yosemite, Apple Pay, and more.

Tech News Today

Samsung announced that its Knox security platform received NSA approval for use by US Government.

This Week in Enterprise Tech

Enterprise Storage with Howard Marks

iPad Today

Clips for smart copy/paste, Flickr's new iPad app, iOS 8.1

Tech News 2Night

iOS 8.1 is now available

Triangulation

Writer, editor, and professional bohemian.

Coding 101 32

C# Abstract Classes and Interfaces

August 28 2014

Hosts: Fr. Robert Ballecer, SJ and Shannon Morse

Guest: Lou Maresca

The Code for today's show is available at our: Github

Snubs Compiled
No Viewer Submitted Code, however we did get some useful tips for C# from our community:

Cosmic Ray links us to a C# Fundamentals series that's super useful for newbies!

Nathan says learning the syntax of the languages is great, but you need to know how to problem solve!

Kelvin links us to Mono, for Mac users

Joe gives us info on how to get C# running via notepad!

Ivory Tower
Interfaces, Classes, & Abstract Classes

Remember from last week that "Classes" are blueprints
- They are a collection of Methods, variables, properties and events
- Classes DO NOT EXIST until they are created (i.e. the difference between having a blueprint and the building built from those blueprints)
- When an instance of a class is "created" -- and "object" is born

Declaring a Class
public class C101

{

//Fields, methods, properties, events
// everything in the "blue print" goes in here

}

Creating an OBJECT of a class:
C101 object1 = new C101();

** One of the topics that was covered towards the end of our "Code Warrior" section last week, was the idea of inheritance.
-- You can make new classes that inherit their members from another class, with derrivations from the original class.

Inheriting from a class
public class Module4 : C101

{

//Fields, methods, properties, events
//everything in the ""blue print"" goes in here

}

** However, there's another way to do that... another way that perhaps is MORE suited for inheritance and derrivation than a class... an ABSTRACT CLASS

Now let's talk about "Abstract Classes"
* If classes are blueprints --- things that are ready to create --- to turn into objects, then "ABSTRACT Classes" are architectural designs.
-- They have the right shape of the thing to be created
-- They have much of the information needed to create the thing being created
-- But they are not complete
-- They cannot be instantiated - (They cannot not be "created" into an object)

* The sole purpose of an abstract class is to act as a "base" for inheritance
-- They cannot be instantiated, but a derrivative class, which inherits the abstract members from the abstract class, can be.
-- That derrivative class must provide proper implementation for all the abstract members of the abstract class, then it CAN create an object. (It complete's the blueprints)

Declaring an abstract class
public abstract class C101

{

//Fields, methods, properties, events
//everything in the ""blue print goes in here

public abstract void menu()

{

}

}

Inheriting from an abstract class
public class Module4 : C101

{

public void menu()

{

Console.WriteLine("This is a Menu");

}

}

* The inherited class from C101 MUST provide implementation for any abstract members within that class.

A few things about Abstract Classes:
1. They are created with the keyword "abstract"
2. They are incomplete and therefore CANNOT be instantiated. (an object cannot be created from the class)
3. Abstract classes and incomplete, and therefore can only be used as a base class
4. Non-abstract classes that are derived from abstract classes MUST provide proper implementation for any abstract members that are inherited from the abstract class.

Why have an Abstract Class?
* Abstract classes ENFORCE a particular hierarchy - They FORCE those who are inheriting from the class to code in a particular way to complete implementation.
* Abstract classes give us "parent" classes from which we can derive objects with customized implementation
* Going back to the blueprint:
-- An abstract class can give us the overview of what an object should look like, but then each derrivative class can implement the pieces of the abstract class as then need to be to best suit function

Let's talk about an Interface
* An Interface is like an Abstract class in that it can be used to define hierarchies for any sub-classes
* Unlike an Abstract Class, an Interface has NO body.
-- It's just the definitions of methods, with no body whatsoever.

Get in Touch With Us!

* Subscribe and get Coding 101 automatically at TWiT.tv!
* Follow PadreSJ and Snubs on Twitter.
* Watch the show live and join the chatroom every Thursday at 1:30pm PST.
* Email us at Padre@twit.tv and Shannon@twit.tv.
* Join our Google+ Community!
* Check out our transcripts.