Lab Sheet 4: Exploring Array Basics Exercises

Part 1: Array Declaration and Initialization

Exercise 1.1: Creating Your First Array

1. Create a new C# Windows Forms Application project named "ArrayPracticals"

2. Add the following controls to Form1:

   • 1 Button (btnDisplay)

   • 1 ListBox (lstOutput)

   • 1 Label (lblTitle) - Set text as "Array Display"

3. Write code in the button click event to:

   • Declare a string array named fruits with values: "Mango", "Banana", "Apple", "Orange", "Papaya"

   • Display each element in the listbox using a for loop

Expected Output: All fruit names should appear in the listbox when button is clicked.

Exercise 1.2: Integer Array Operations

1. Add another button (btnNumbers) with text "Display Numbers"

2. Declare an integer array: int[] numbers = {45, 12, 78, 23, 56, 89, 34}

3. Display the following in the listbox:

   • Total number of elements

   • Each number with its index (e.g., "Index 0: 45")

Part 2: Using foreach Loop

Exercise 2.1: Student Marks Display

1. Add a new button (btnMarks) with text "Show Marks"

2. Clear the listbox before adding new items

3. Create an integer array for student marks: {67, 45, 89, 92, 73, 55, 81}

4. Use a foreach loop to display all marks in the listbox

5. Calculate and display the average marks at the end

Hint: Sum all marks in the foreach loop and divide by array length

Part 3: Array Sorting

Exercise 3.1: Sorting Cities

1. Design a new form with:

   • 1 ListBox (lstCities) - for displaying cities

   • 1 Button (btnOriginal) - text: "Original Order"

   • 1 Button (btnSort) - text: "Sort Alphabetically"

   • 1 Label - title: "Sri Lankan Cities"

2. Declare a string array: {"Colombo", "Kandy", "Galle", "Jaffna", "Anuradhapura", "Batticaloa", "Trincomalee"}

3. When btnOriginal is clicked:

   • Clear the listbox

   • Display cities in original order

4. When btnSort is clicked:

   • Clear the listbox

   • Sort the array using Array.Sort()

   • Display sorted cities

Part 4: Array Reversal

Exercise 4.1: Working with Array.Reverse()

1. Add the following controls to your form:

   • 1 Button (btnReverse) - text: "Reverse All"

   • 1 Button (btnReversePartial) - text: "Reverse First 3"

   • 1 Button (btnReset) - text: "Reset"

2. Create an array: string[] colors = {"Red", "Green", "Blue", "Yellow", "Purple", "Orange"}

3. Implement the following functionality:

   • btnReverse: Reverse all elements and display

   • btnReversePartial: Reverse only the first 3 elements using Array.Reverse(colors, 0, 3)

   • btnReset: Display original order

Challenge: After reversing, what happens to the original array? Test and observe.

Part 5: Using AddRange() Method

Exercise 5.1: Multiple Arrays to ListBox

1. Create a new form with:

   • 1 ListBox (lstVehicles)

   • 1 Button (btnCars) - text: "Show Cars"

   • 1 Button (btnBikes) - text: "Show Bikes"

   • 1 Button (btnAll) - text: "Show All"

2. Declare two arrays:

    string[] cars = {"Toyota", "Honda", "Nissan", "Suzuki"};
    string[] bikes = {"Yamaha", "Bajaj", "TVS", "Hero"};
   

3. Implement:

   • btnCars: Use AddRange() to add all cars to listbox

   • btnBikes: Clear listbox and add all bikes

   • btnAll: Add both arrays to listbox (cars first, then bikes)

Part 6: Practical Application

Exercise 6.1: Student Grade Management System

Create a comprehensive application with the following features:

Form Design:

• TextBox (txtMarks) - for entering marks

• Button (btnAdd) - to add marks to array

• Button (btnSort) - to sort marks in ascending order

• Button (btnHighest) - to display highest mark

• Button (btnLowest) - to display lowest mark

• Button (btnClear) - to clear all data

• ListBox (lstMarks) - to display marks

• Label (lblCount) - to show total number of marks entered

Requirements:

1. Use a List or create a dynamic solution to store multiple mark entries

2. Validate that marks are between 0-100

3. Display all marks in the listbox after each operation

4. Use Array.Sort() for sorting functionality

5. Show appropriate messages using MessageBox.Show()

Bonus Challenge: Add a button to calculate and display:

• Average marks

• Pass percentage (marks >= 50)

• Grade distribution (A: 75-100, B: 65-74, C: 50-64, F: <50)

Tips for Success

• Always clear the listbox before adding new items to avoid duplication

• Use meaningful variable names

• Add comments to explain your code logic

• Test each functionality thoroughly before moving to the next exercise

Good Luck with Your Lab Work!