Custom exception classes in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a custom exception class named MyException.

Kotlin

class MyException : [1]("Custom error occurred")

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AException

BError

CThrowable

DRuntimeException

Attempts:

3 left

💡 Hint

Common Mistakes

Using Error instead of Exception as the base class.

Forgetting to extend any class.

The custom exception class should inherit from Exception, the standard base class for custom exceptions in Kotlin.

2fill in blank

medium

Complete the code to throw the custom exception MyException.

Kotlin

fun checkValue(value: Int) {
    if (value < 0) {
        [1] MyException()
    }
}

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Areturn

Bthrow

Craise

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'raise' which is from other languages.

Using 'return' which just exits the function.

In Kotlin, you use throw to throw exceptions.

3fill in blank

hard

Fix the error in the custom exception class constructor to accept a message parameter.

Kotlin

class MyException(message: String) : Exception([1]) {}

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Amessage

B"message"

Cmsg

Dthis.message

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a string literal instead of the variable.

Using an undefined variable name.

The constructor parameter message should be passed directly to the base Exception class.

4fill in blank

hard

Fill both blanks to create a custom exception with a default message and a secondary constructor.

Kotlin

class MyException : Exception {
    constructor() : super([1])
    constructor(message: String) : super([2])
}

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A"Default error"

Bmessage

C"Error occurred"

Dmsg

Attempts:

3 left

💡 Hint

Common Mistakes

Using undefined variable names.

Passing string literals where variables are expected.

The default constructor passes a fixed string, and the secondary constructor passes the message parameter.

5fill in blank

hard

Fill all three blanks to create a custom exception class with a message property and override the toString method.

Kotlin

class MyException(val [1]: String) : Exception([2]) {
    override fun toString(): String {
        return "MyException: " + [3]
    }
}

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

Amessage

Dmsg

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the property and constructor parameter.

Not returning the message in toString.

The property and constructor parameter are named message, and the toString method returns it.