Throwing custom exceptions in Java - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

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

Java

public class MyException extends [1] {
}

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ARuntimeException

BString

CExceptionHandler

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Extending a non-exception class like String or int.

Forgetting to extend any class.

The custom exception class should extend RuntimeException or Exception. Here, RuntimeException is used.

2fill in blank

medium

Complete the constructor of the custom exception to accept a message.

Java

public class MyException extends RuntimeException {
    public MyException([1] String message) {
        super(message);
    }
}

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Aprivate

Bfinal

Cpublic

Dstatic

Attempts:

3 left

💡 Hint

Common Mistakes

Using access modifiers like private or public on parameters.

Omitting the parameter type.

The constructor parameter can be declared final to prevent modification, but it's optional. Here, final is used as a good practice.

3fill in blank

hard

Fix the error in throwing the custom exception with a message.

Java

throw new MyException([1]);

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Anew MyException()

BException

C"Error occurred"

DMyException

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the class name instead of a message.

Not passing any argument.

When throwing the exception, you must pass a string message to the constructor, like "Error occurred".

4fill in blank

hard

Fill both blanks to throw a custom exception when a number is negative.

Java

if (number [1] 0) {
    throw new MyException([2]);
}

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A<

B"Negative number not allowed"

C>

D"Number is positive"

Attempts:

3 left

💡 Hint

Common Mistakes

Using > instead of < for the condition.

Throwing exception with wrong message.

The condition checks if the number is less than zero, then throws the exception with the message "Negative number not allowed".

5fill in blank

hard

Fill all three blanks to define and throw a custom exception with a message including the invalid value.

Java

public class MyException extends RuntimeException {
    public MyException(String message) {
        super(message);
    }
}

int value = -5;
if (value [1] 0) {
    throw new MyException("Invalid value: " + [2] + [3]);
}

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A<

Bvalue

C"!"

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using > instead of < in the condition.

Not concatenating the message parts correctly.

The code checks if value is less than zero, then throws MyException with a message showing the invalid value followed by an exclamation mark.