Finally block behavior in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of finally block with return in try

What is the output of this Kotlin code snippet?

Kotlin

fun test(): Int {
    try {
        return 1
    } finally {
        println("Finally block executed")
    }
}

fun main() {
    println(test())
}

A Compilation error

B

Finally block executed
1

C

Finally block executed
0

D

1
Finally block executed

💡 Hint

Remember that finally block runs even if try returns.

In Kotlin, the finally block always runs after the try block, even if the try block returns. So the println in finally executes before the returned value is printed.

❓ Predict Output

intermediate

Effect of exception and finally block

What will be printed when this Kotlin code runs?

Kotlin

fun test(): Int {
    try {
        throw Exception("Error")
    } finally {
        println("Finally block runs")
    }
}

fun main() {
    try {
        test()
    } catch (e: Exception) {
        println(e.message)
    }
}

A

Finally block runs
Error

B Finally block runs

C

Error
Finally block runs

D No output, program crashes

💡 Hint

Finally block runs even if exception is thrown.

The exception is thrown in try, but before propagating, finally block runs and prints its message. Then the exception is caught in main and its message is printed.

🔧 Debug

advanced

Why does this finally block not execute?

Consider this Kotlin code. Why does the finally block not print anything?

Kotlin

fun test(): Int {
    try {
        System.exit(0)
    } finally {
        println("Finally block executed")
    }
}

fun main() {
    test()
}

A Because println is inside try, not finally.

B Because finally block only runs if exception is thrown.

C Because System.exit terminates the JVM immediately, skipping finally.

D Because the code has a syntax error and does not compile.

💡 Hint

System.exit stops the program immediately.

System.exit(0) stops the whole program immediately, so the finally block is never reached or executed.

📝 Syntax

advanced

Identify the syntax error in finally usage

Which option contains a syntax error related to the finally block in Kotlin?

A try { println("Try") } catch (e: Exception) { println("Catch") } finally { println("Finally") }

B try { println("Try") } finally println("Finally")

C } )"yllaniF"(nltnirp { yllanif } )"hctaC"(nltnirp { )noitpecxE :e( hctac } )"yrT"(nltnirp { yrt

D try { println("Try") } catch (e: Exception) { println("Catch") } finally println("Finally")

💡 Hint

Finally block must be a block, not a single statement without braces if catch is present.

In Kotlin, if a finally block is present after a catch block, it must be a block enclosed in braces. Option D misses braces around finally block, causing syntax error.

🧠 Conceptual

expert

Finally block and variable modification with return

What is the output of this Kotlin code?

Kotlin

fun test(): Int {
    var x = 1
    try {
        return x
    } finally {
        x = 2
        println("Finally block: x = $x")
    }
}

fun main() {
    println("Returned value: ${test()}")
}

A

Finally block: x = 2
Returned value: 1

B

Finally block: x = 2
Returned value: 2

C

Returned value: 1
Finally block: x = 2

D Compilation error

💡 Hint

Return value is determined before finally block runs.

The return value is evaluated before finally block runs, so it returns the original x=1. The finally block changes x to 2 and prints it, but this does not affect the returned value.