Question

Explain to me the following Object-oriented concepts:

class, object (and the difference between the two)
instantiation
method (as opposed to, say, a C function)
virtual method, pure virtual method
class/static method
static/class initializer
constructor
destructor/finalizer
superclass or base class
subclass or derived class
inheritance
encapsulation
multiple inheritance (and give an example)
delegation/forwarding
composition/aggregation
abstract class

Answer 1

interface/protocol (and different from abstract class)
method overriding
method overloading (and difference from overriding)
polymorphism (without resorting to examples)
is-a versus has-a relationships (with examples)
method signatures (what's included in one)
method visibility (e.g. public/private/other)

Answer 2

Elementary stuff, and I hope that 2 or 3 examples will explain them well :-D \[\tiny\text{please no animal/car analogies :(}\]

Answer 3

Uh... not that I'm against explaining it - but maybe a textbook would be better? haha. I mean, there is a lot of content here.

Answer 4

a class is basically a definition of a group of things, an object is a thing that is part of a class. ex.

Public Class automobile
Public color As String
Public doors As Integer
Public fuel As Integer
Public MPG As Integer

Public Sub New(ByVal ncolor As String, ByVal ndoors As Integer, ByVal nfuel As Integer, ByVal nMPG As Integer)

color = ncolor
doors = ndoors
fuel = nfuel
MPG = nMPG
End Sub
Public Function travel()
Return fuel * MPG
End Function
End Class

this is a class. this class is called automobile. and really the only thing needed to make a class is the top part "public class automobile." from there you can give your class properties and functions. like if i want to see how far an automobile can travel i would write (Insert name of automobile here).travel and it would do that function.

this is an example of an object.


Module Module1

Sub Main()
Dim truck As New automobile("white", 4, 28, 14)
Dim van As New automobile("gold", 5, 22, 24)
Dim Dtruck As New automobile("silver", 4, 30, 18)
System.Console.WriteLine(truck.travel)
End Sub

End Module


the truck, van, and Dtruck are all objects of the class "automobile." as you'll notice i've told the program to "System.Console.WriteLine(truck.travel)" that will take the MPG of the car and the capacity of the tank, multiply them, and print the answer on the screen. if you'll notice the colors and numbers after the dim () as new automobile. those are because in the class i called a (public sub new) and that makes it so i have to type in the specific info in that spot. also at the top of the class i wrote "public color as string" those are the properties basically. color is a property and so is fuel MPG and doors.


and the rest of the stuff either i dont fully understand myself or i just dont know. :/ sorry. im a student myself :/ good luck!

Answer 5

Could have noted that Public Sub New() is a constructor :-D

Answer 6

haha to be honest i didnt know that. :) but thanks. now i do :)