Finally block behavior in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of try-finally without catch

What is the output of this C# code snippet?

C Sharp (C#)

using System;
class Program {
  static void Main() {
    try {
      Console.WriteLine("Start");
    } finally {
      Console.WriteLine("Finally block executed");
    }
  }
}

A Finally block executed\nStart

B No output

C Start\nFinally block executed

D Start

💡 Hint

Remember that the finally block always runs after the try block, even if no exception occurs.

The try block runs first and prints "Start". Then the finally block runs and prints "Finally block executed". So both lines appear in order.

❓ Predict Output

intermediate

Finally block with exception thrown

What will be printed when this code runs?

C Sharp (C#)

using System;
class Program {
  static void Main() {
    try {
      Console.WriteLine("Before exception");
      throw new Exception("Error");
    } finally {
      Console.WriteLine("In finally");
    }
  }
}

A Before exception\nIn finally\nUnhandled Exception: Error

B In finally\nBefore exception\nUnhandled Exception: Error

C Before exception\nUnhandled Exception: Error

D No output

💡 Hint

The finally block runs even if an exception is thrown, before the exception propagates.

The try block prints "Before exception" then throws. The finally block runs and prints "In finally". Then the exception is unhandled and shown.

❓ Predict Output

advanced

Return value with finally modifying variable

What is the output of this program?

C Sharp (C#)

using System;
class Program {
  static int Test() {
    int x = 1;
    try {
      return x;
    } finally {
      x = 2;
      Console.WriteLine("Finally executed");
    }
  }
  static void Main() {
    Console.WriteLine(Test());
  }
}

A Finally executed\n1

B Finally executed\n2

C 1\nFinally executed

D 2\nFinally executed

💡 Hint

The return value is determined before finally runs, even if finally changes the variable.

The method returns x which is 1. The finally block runs and prints "Finally executed" but does not change the returned value.

❓ Predict Output

advanced

Finally block with return inside it

What will this program print?

C Sharp (C#)

using System;
class Program {
  static int Test() {
    try {
      return 1;
    } finally {
      return 2;
    }
  }
  static void Main() {
    Console.WriteLine(Test());
  }
}

A Runtime exception

B 1

C Compilation error

D 2

💡 Hint

A return in finally overrides any previous return from try.

The finally block's return replaces the try block's return, so the method returns 2.

🧠 Conceptual

expert

Behavior of finally with exception and return

Consider this code snippet. What happens when it runs?

C Sharp (C#)

using System;
class Program {
  static int Test() {
    try {
      throw new Exception("Error");
    } finally {
      return 42;
    }
  }
  static void Main() {
    Console.WriteLine(Test());
  }
}

A Prints nothing and program crashes

B Prints 42 and suppresses the exception

C Throws the exception and does not print anything

D Compilation error due to return in finally

💡 Hint

A return in finally block suppresses any exception thrown in try.

The exception is thrown but the finally block returns 42, which overrides the exception. So 42 is printed and no exception propagates.