Switch statement execution in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of switch with fall-through using goto case

What is the output of this C# code snippet?

C Sharp (C#)

int x = 2;
switch (x)
{
    case 1:
        Console.WriteLine("One");
        break;
    case 2:
        Console.WriteLine("Two");
        goto case 3;
    case 3:
        Console.WriteLine("Three");
        break;
    default:
        Console.WriteLine("Default");
        break;
}

A Two\nThree

B Two

C Three

D Default

💡 Hint

Remember that 'goto case' transfers control to another case label.

When x is 2, it prints "Two" then jumps to case 3 and prints "Three" before breaking.

❓ Predict Output

intermediate

Switch expression output with pattern matching

What is the output of this C# code using a switch expression?

C Sharp (C#)

object obj = 5;
string result = obj switch
{
    int i when i > 0 => "Positive integer",
    int i when i < 0 => "Negative integer",
    string s => "String",
    _ => "Other"
};
Console.WriteLine(result);

A Positive integer

B Negative integer

C String

D Other

💡 Hint

Check the type and condition matched in the switch expression.

The object is an int with value 5, which is greater than 0, so it matches the first pattern.

🔧 Debug

advanced

Identify the error in switch statement

What error does this C# code produce?

C Sharp (C#)

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

A Runtime error: fall-through not allowed

B Compile-time error: duplicate case labels

C No error, output is Monday\nTuesday

D Compile-time error: missing break in case 1

💡 Hint

C# does not allow implicit fall-through between cases.

C# requires each case to end with break or other jump statement unless it ends with a goto or return. Missing break causes compile error.

❓ Predict Output

advanced

Switch with multiple case labels and default

What is the output of this C# switch statement?

C Sharp (C#)

char grade = 'B';
switch (grade)
{
    case 'A':
    case 'B':
        Console.WriteLine("Pass");
        break;
    case 'C':
        Console.WriteLine("Average");
        break;
    default:
        Console.WriteLine("Fail");
        break;
}

A Average

B Fail

C Pass

D No output

💡 Hint

Multiple case labels can share the same code block.

Grade 'B' matches case 'B', which shares code with case 'A', printing "Pass".

🧠 Conceptual

expert

Switch statement behavior with nullable types

Given the following code, what is the output?

C Sharp (C#)

int? number = null;
switch (number)
{
    case null:
        Console.WriteLine("Null value");
        break;
    case > 0:
        Console.WriteLine("Positive number");
        break;
    default:
        Console.WriteLine("Other number");
        break;
}

A Compile-time error

B Null value

C Other number

D Positive number

💡 Hint

Switch supports pattern matching including null checks on nullable types.

The nullable int is null, so it matches the 'case null' pattern and prints "Null value".