Review Questions

Which digits, and in which order, will be printed when the following program is run?

public class MyClass {
    public static void main(String[] args) {
        int k=0;
        try {
            int i = 5/k;
        } catch (ArithmeticException e) {
            System.out.println("1");
        } catch (RuntimeException e) {
            System.out.println("2");
            return;
        } catch (Exception e) {
            System.out.println("3");
        } finally {
            System.out.println("4");
        }
        System.out.println("5");
    }
}

Select the one correct answer.

Given the following program, which statements are true?

public class Exceptions {
    public static void main(String[] args) {
        try {
            if (args.length == 0) return;
            System.out.println(args[0]);
        } finally {
            System.out.println("The end");
        }
    }
}

Select the two correct answers.

What will be the result of attempting to compile and run the following program?

public class MyClass {
    public static void main(String[] args) {
        RuntimeException re = null;
        throw re;
    }
}

Select the one correct answer.

Which statements are true?

Select the two correct answers.

Which digits, and in which order, will be printed when the following program is compiled and run?

public class MyClass {
    public static void main(String[] args) {
        try {
            f();
        } catch (InterruptedException e) {
            System.out.println("1");
            throw new RuntimeException();
        } catch (RuntimeException e) {
            System.out.println("2");
            return;
        } catch (Exception e) {
            System.out.println("3");
        } finally {
            System.out.println("4");
        }
        System.out.println("5");
    }
    // InterruptedException is a direct subclass of Exception.
    static void f() throws InterruptedException {
        throw new InterruptedException("Time for lunch.");
    }
}

Select the one correct answer.

Which digits, and in which order, will be printed when the following program is run?

public class MyClass {
    public static void main(String[] args) throws InterruptedException {
        try {
            f();
            System.out.println("1");
        } finally {
            System.out.println("2");
        }
        System.out.println("3");
    }
    // InterruptedException is a direct subclass of Exception.
    static void f() throws InterruptedException {
        throw new InterruptedException("Time to go home.");
    }
}

Select the one correct answer.

What is wrong with the following code?

public class MyClass {
    public static void main(String[] args) throws A {
        try {
            f();
        } finally {
            System.out.println("Done.");
        } catch (A e) {
            throw e;
        }
    }

    public static void f() throws B {
        throw new B();
    }
}
class A extends Throwable {}

class B extends A {}

Select the one correct answer.

What is the minimal list of exception classes that the overriding method f() in the following code must declare in its throws clause before the code will compile correctly?

class A {
   // InterruptedException is a direct subclass of Exception.
    void f() throws ArithmeticException, InterruptedException {
        div(5, 5);
    }
    int div(int i, int j) throws ArithmeticException {
        return i/j;
    }
}

public class MyClass extends A {
    void f() /* throws [...list of exceptions...] */ {
        try {
            div(5, 0);
        } catch (ArithmeticException e) {
            return;
        }
        throw new RuntimeException("ArithmeticException was expected.");
    }
}

Select the one correct answer.

What, if anything, would cause the following code not to compile?

class A {
    void f() throws ArithmeticException {
        //...
    }
}

public class MyClass extends A {
    public static void main(String[] args) {
        A obj = new MyClass();

        try {
            obj.f();
        } catch (ArithmeticException e) {
            return;
        } catch (Exception e) {
            System.out.println(e);
            throw new RuntimeException("Something wrong here");
        }
    }
    // InterruptedException is a direct subclass of Exception.
    void f() throws InterruptedException {
        //...
    }
}

Select the one correct answer.