Lab 3

Exercise 1

The HelloDogs application presented in the lecture is available on teachmat. Download the code and make sure you understand every single line - if something is not clear, go back to the lecture notes. If it is still not clear, ask a tutor.

Exercise 2

Make the following changes to the HelloDogs application :

a) In the class Dog, add the following private variables:o dogHeight - an instance variable of integer type (height in cm)o dogColour – an instance variable – what type should it be?o noOfLEgs – a class (static) variable

b) In the class Dog, create properties to encapsulate the variables created in the previous task (a)

Note: Use the wizard (as explained in the lecture) Hint: the property for the noOfLegs will be static

A RichTextBox

A Button

c) In the class Dog, add a new constructor that takes the following parameters

o dogHeight o dogColour o breed

d) In the class Dog, add a private method called IsBig that returns a Boolean and takes a parameter of type integer. If that parameter is <50, the method should return false. Otherwise it should return true

e) In the class Dog, change the method GetSpeech so

o using the method IsBig created in point (d) checks if the dog is big or not.

o it returns all details about the dog (including dogHeight , dogColour). Also, the dog should state if it is big or not.

Hint: It cannot return the noOfLegs as it is a static variable

f) In the class DogChorus, create 2 more dogs (instances of class Dog) using the constructor you created in point(c)

g) In the class DogChorus, change the GetOutput () method so:

o it returns details of all dogs created including the number of leges that all dogs have

Hint: you need to call the static NoOfLegs property you created at point (b) through the class name

h) On your Form1 user interface add 4 textboxes. Through the new textboxes you should be able to change the instance variables breed, dogHeight , dogColour and barkSound of a dog.

Add a new button that will create new dogs. When the button is clicked a new dog instance will be created. This dog instance will have the details specified in the textboxes. The rich text box should display the new dog’s details, including dogHeight , dogColour, noOfLegs and if the dog thinks it is a big dog or not.

Exercise 3

Download Classes and Objects Tutorial from teachmat.Build the temperature converter application as presented in the tutorial. It should have the extra following classes

Class Conversions ClassTemperature

Add a new constructor to the class Temperature Should take 3 parameters:

o double temperature, bool CtoF, DateTime myDate

On the form add a new control - DateTimePicker- from toolbox Add a new button

o When clicked create an object of type Temperature for which you can pass other days than today though the DateTimePicker

o Add the temperatures to your log.

Optional Exercise

In class Conversions you have 2 methods, each with one parameter. By

default, the parameters are value type. Change them to ref type and see what

impact it has on the program.