Switch statement execution in C Sharp (C#) - Mini Project: Build & Apply

Switch Statement Execution

📖 Scenario: Imagine you are building a simple program that tells the day type based on the day number. This is like a small calendar helper that says if a day is a weekday or weekend.

🎯 Goal: You will create a program that uses a switch statement to print whether a day number (1 to 7) is a weekday or weekend.

📋 What You'll Learn

Create an integer variable called dayNumber with a value from 1 to 7.

Use a switch statement on dayNumber.

Print "Weekday" for days 1 to 5.

Print "Weekend" for days 6 and 7.

Print "Invalid day" for any other number.

💡 Why This Matters

🌍 Real World

Switch statements help programs make decisions based on different values, like menus, commands, or day types.

💼 Career

Understanding switch statements is important for writing clear and efficient code in many software development jobs.

1

Create the day number variable

Create an integer variable called dayNumber and set it to 3.

C Sharp (C#)

# Your code here

Hint

Use int dayNumber = 3; to create the variable.

2

Start the switch statement

Write a switch statement using dayNumber as the expression.

C Sharp (C#)

int dayNumber = 3;

// Start the switch statement on dayNumber
# Your code here

Hint

Use switch (dayNumber) { } to start the switch.

3

Add cases for weekdays and weekends

Inside the switch, add cases for 1 to 5 that print "Weekday", cases for 6 and 7 that print "Weekend", and a default case that prints "Invalid day".

C Sharp (C#)

int dayNumber = 3;

switch (dayNumber)
{
    // Add cases for 1 to 5 to print "Weekday"
    // Add cases for 6 and 7 to print "Weekend"
    // Add default case to print "Invalid day"
# Your code here
}

Hint

Group cases 1 to 5 together to print "Weekday". Group 6 and 7 to print "Weekend". Use default for invalid days.

4

Run and display the output

Run the program and observe the output printed by the switch statement.

C Sharp (C#)

int dayNumber = 3;

switch (dayNumber)
{
    case 1:
    case 2:
    case 3:
    case 4:
    case 5:
        System.Console.WriteLine("Weekday");
        break;
    case 6:
    case 7:
        System.Console.WriteLine("Weekend");
        break;
    default:
        System.Console.WriteLine("Invalid day");
        break;
}

// Run the program to see the output
# Your code here

Hint

The output should be Weekday because dayNumber is 3.

Practice

1.

What is the main purpose of a switch statement in C#?

easy

A. To repeat a block of code multiple times

B. To execute different code blocks based on the value of a variable

C. To define a function

D. To declare variables

Solution

1. Step 1: Understand the role of switch

   A switch statement selects one of many code blocks to execute based on a variable's value.

2. Step 2: Compare with other options

   Loops repeat code, functions define reusable code, and variable declarations create variables, none of which match switch's purpose.

3. Final Answer:

   To execute different code blocks based on the value of a variable -> Option B

4. Quick Check:

   Switch chooses code by value = A [OK]

Hint: Switch chooses code based on variable value [OK]

Common Mistakes:

• Confusing switch with loops
• Thinking switch defines functions
• Believing switch declares variables

2.

Which of the following is the correct syntax to start a switch statement in C#?

?

easy

A. switch (variable) { case 1: break; }

B. switch variable { case 1: break; }

C. switch (variable) case 1: break;

D. switch { variable case 1: break; }

Solution

1. Step 1: Recall switch syntax

   The correct syntax uses parentheses around the variable and braces around cases: switch (variable) { ... }

2. Step 2: Check each option

   switch (variable) { case 1: break; } matches correct syntax; others miss parentheses or braces or have wrong order.

3. Final Answer:

   switch (variable) { case 1: break; } -> Option A

4. Quick Check:

   Parentheses and braces required = C [OK]

Hint: Switch needs (variable) and { cases } syntax [OK]

Common Mistakes:

• Omitting parentheses around variable
• Missing braces around cases
• Incorrect order of keywords

3.

What will be the output of this C# code?

int day = 3;
switch (day) {
  case 1:
    Console.WriteLine("Monday");
    break;
  case 2:
    Console.WriteLine("Tuesday");
    break;
  case 3:
    Console.WriteLine("Wednesday");
    break;
  default:
    Console.WriteLine("Invalid day");
    break;
}

medium

A. Wednesday

B. Monday

C. Tuesday

D. Invalid day

Solution

1. Step 1: Identify the switch variable value

   The variable day is 3.

2. Step 2: Match case with variable

   Case 3 matches, so it prints "Wednesday" and then breaks.

3. Final Answer:

   Wednesday -> Option A

4. Quick Check:

   day=3 prints Wednesday [OK]

Hint: Match variable value to case label [OK]

Common Mistakes:

• Forgetting break causes fall-through
• Choosing default when case matches
• Mixing case numbers and output

4.

Find the error in this switch statement and select the fix:

int number = 2;
switch (number) {
  case 1:
    Console.WriteLine("One");
  case 2:
    Console.WriteLine("Two");
  default:
    Console.WriteLine("Default");
}

medium

A. Add semicolon after switch statement

B. Remove the default case

C. Change switch to if

D. Add break; after each case block

Solution

1. Step 1: Identify missing break statements

   Each case lacks a break, causing fall-through to next cases.

2. Step 2: Fix by adding breaks

   Adding break after each case stops fall-through and executes only matched case.

3. Final Answer:

   Add break; after each case block -> Option D

4. Quick Check:

   Break stops fall-through = A [OK]

Hint: Add break to stop fall-through in switch [OK]

Common Mistakes:

• Ignoring fall-through behavior
• Removing default case unnecessarily
• Misusing if instead of switch

5.

Given this code, what will be printed?

int score = 85;
switch (score / 10) {
  case 10:
  case 9:
    Console.WriteLine("Excellent");
    break;
  case 8:
    Console.WriteLine("Good");
    break;
  case 7:
  case 6:
    Console.WriteLine("Pass");
    break;
  default:
    Console.WriteLine("Fail");
    break;
}

hard

A. Excellent

B. Fail

C. Good

D. Pass

Solution

1. Step 1: Calculate switch expression value

   score is 85, so score / 10 is 8 (integer division).

2. Step 2: Match case for value 8

   Case 8 prints "Good" and breaks.

3. Final Answer:

   Good -> Option C

4. Quick Check:

   85/10=8 prints Good [OK]

Hint: Divide score by 10, match case labels [OK]

Common Mistakes:

• Not using integer division
• Missing combined cases for 9 and 10
• Choosing default incorrectly