Why error handling matters in Kotlin - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch an exception and print a message.

Kotlin

try {
    val result = 10 / [1]
    println("Result: $result")
} catch (e: Exception) {
    println("Error occurred")
}

Drag options to blanks, or click blank then click option'

A0

Bnull

C2

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-zero number won't cause an error here.

Dividing by zero causes an exception, so catching it shows why error handling matters.

2fill in blank

medium

Complete the code to throw an exception when input is negative.

Kotlin

fun checkNumber(num: Int) {
    if (num < [1]) {
        throw IllegalArgumentException("Negative number not allowed")
    }
}

Drag options to blanks, or click blank then click option'

A10

B1

C-1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 or -1 changes the condition meaning.

We check if the number is less than zero to detect negative numbers.

3fill in blank

hard

Fix the error in the catch block to print the exception message.

Kotlin

try {
    val data = "abc".toInt()
} catch (e: Exception) {
    println(e[1])
}

Drag options to blanks, or click blank then click option'

A.message()

B.message

C.getMessage()

D.toString()

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses causes a syntax error.

In Kotlin, exception messages are accessed with the property message without parentheses.

4fill in blank

hard

Fill both blanks to handle a NumberFormatException and print a custom message.

Kotlin

try {
    val num = "abc".toInt()
} catch (e: [1]) {
    println("[2]")
}

Drag options to blanks, or click blank then click option'

ANumberFormatException

BIllegalArgumentException

CNullPointerException

DArithmeticException

Attempts:

3 left

💡 Hint

Common Mistakes

Catching wrong exception types.

We catch NumberFormatException and print a message explaining the error.

5fill in blank

hard

Fill all three blanks to create a function that safely parses an integer or returns null.

Kotlin

fun safeParseInt(str: String): Int? {
    return try {
        str[1]toInt()
    } catch (e: [2]) {
        [3]
    }
}

Drag options to blanks, or click blank then click option'

A.

BNumberFormatException

Cnull

D!!

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong exception type or returning wrong value.

The dot operator calls toInt(). We catch NumberFormatException and return null if parsing fails.