1. Review of Classes and Arrays
Lecture 3
Review of Classes and Arrays
Richard Gesick

2. Defining the class Methods: Constructor: Properties
public, private or protected
return or not
Properties
get
set
Constructor:
same name as class
public visibility
default and overloaded
Class instance variables
Should normally be private

3. Class definition and default constructor
public class Trophy {
private string name;
private int points = 10;
public Trophy()
name = "Yeah that's a problem";
points = 0; }

4. Overloaded Constructor
public Trophy (string n, int p) {
name = n;
points = p; }

5. public string Name { get return name; }
Properties
public int Points {
get
{ return points; }
set
if (value > 0)
points = value; }
public string Name {
get
return name; }

6. Override of the toString method
public override string ToString( ) {
return name + " (" + points + ")"; }

7. Arrays Trophy [] troph; … troph = new Trophy[10]; or
Trophy [] troph = new Trophy[10];
can't use until memory is allocated with new.

8. Array example Trophy[] data_storage; int sum = 0;
Console.Write("How many trophies: ");
int trophie_count;
trophie_count = Int32.Parse(Console.ReadLine());
data_storage = new Trophy [trophie_count];

9. Traversing an array
Use a for, while or do-while starting at index 0 and going thru .Length-1
for(int i=0; i< data_storage.Length;i++)
{ do something }
Or use a foreach loop
foreach(Trophy t in data_storage)
{ do something as long as it doesn't add or remove members of the array }

10. program sample 1

11. Enumerated types
public enum <typeName>{constant1, constant2, … , constantN};
public enum PowerType {Strength, Fly, Speed, MindControl, BugVision};
enum allows us to define a new "type", but this is actually just a place holder for integers.

12. program sample 2

13. Array processing
The simplest processes involve searching ( finding a value, finding the largest or smallest ),or finding a sum, product or average.
Remember to initialize properly.

14. Array processing 2 int[] nums = new int[10]; …
float average = FindAverage(nums);
int min = FindMin(nums);
remember to use "new" to allocate memory for your object.

15. finding the min private static int FindMin (int[] A) {
int temp = A[0];
for (int i = 1; i < 10; i++) {
if (temp > A[i])
temp = A[i]; }
return temp;
notice that the parameters (in this case "nums") when you invoke a method can be called something else in the method itself (in this case "A").  Parameters match in position and type, so the name doesn't matter.

16. finding a sum and or average
private static float FindAverage (int [] B) { int sum = 0;
for (int i = 0; i < 10; i++) {
sum += B[i]; }
return sum / 10f;

17. program sample 3