Exception propagation in Java - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare that the method throws an exception.

Java

public void readFile() [1] IOException {
    // code to read file
}

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

Athrows

Bthrow

CthrowsException

DthrowsError

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'throw' instead of 'throws' in method declaration.

Misspelling the keyword.

The keyword throws declares that a method may throw an exception.

2fill in blank

medium

Complete the code to propagate the exception from methodB to methodA.

Java

public void methodA() [1] Exception {
    methodB();
}

public void methodB() [1] Exception {
    throw new Exception("Error");
}

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

AthrowsException

Bthrow

CthrowsError

Dthrows

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'throw' instead of 'throws' in method declarations.

Not declaring the exception in methodA.

Both methods must declare throws Exception to propagate the exception.

3fill in blank

hard

Fix the error in the code by completing the method signature to propagate the exception.

Java

public void process() [1] IOException {
    FileReader file = new FileReader("file.txt");
}

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

Athrow

Bthrows

CthrowsException

DthrowsError

Attempts:

3 left

💡 Hint

Common Mistakes

Not declaring the exception causes a compile error.

Using 'throw' instead of 'throws'.

The method must declare throws IOException because FileReader constructor throws IOException.

4fill in blank

hard

Fill both blanks to propagate the exception from methodC to methodD.

Java

public void methodD() [1] Exception {
    methodC();
}

public void methodC() [2] Exception {
    throw new Exception("Failure");
}

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

Athrows

Bthrow

CthrowsException

DthrowsError

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'throw' instead of 'throws'.

Not declaring the exception in methodD.

Both methods must declare throws Exception to propagate the exception properly.

5fill in blank

hard

Fill all three blanks to propagate exceptions correctly in nested method calls.

Java

public void start() [1] IOException {
    execute();
}

public void execute() [2] IOException {
    read();
}

public void read() [3] IOException {
    throw new IOException("Read error");
}

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

Athrow

Bthrows

CthrowsException

DthrowsError

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'throw' instead of 'throws'.

Not declaring the exception in all methods.

All methods must declare throws IOException to propagate the checked exception properly.