Java Exceptions

Consider the code in the image. What will happen when the program is executed?

• Program will crash.

• Program will catch an exception in main.

• Program will catch an exception in divide.

• Program will run normally.

Answer explanation

An ArithmeticException is thrown by divide, but not caught in divide nor in main. Therefore, the program crashes.

Consider the code in the image. What happens if a user inputs 2?

• An InputMismatchException is caught in main().

• An IllegalArgumentException is caught in main().

• The program crashes.

• The program calculates and displays asin(2).

Answer explanation

An input of 2 triggers the if-statement in getInput, causing it to throw an IllegalArgumentException which is then caught in main.

Consider the code in the image. What happens if a user inputs the String "sqrt(2)"?

• An InputMismatchException is caught in main().

• An IllegalArgumentException is caught in main().

• The program crashes.

• The program calculates and displays asin(2).

Answer explanation

An input of sqrt(2) has letters and is therefore considered a String. This will cause Java to automatically throw an InputMismatchException, which is caught in main.

Consider the code in the image. What happens when this program is executed?

• An Exception is caught in method1.

• An Exception is caught in method2.

• An Exception is caught in method3.

• The program crashes.

Answer explanation

This program starts in main, then transfers control to method1, then to method3. An Exception is thrown by method3, and because it can't be caught in method3, Java tries method1 next, where it is caught.

Which of these best explains how try-catch blocks differ from throw statements?

• try-catch blocks are handled locally, but throw statements can propagate through the call stack

• try-catch block only catch exceptions, and throw statements only throw exceptions

• try-catch blocks only try to execute code, but throw statements always work

• try-catch blocks are written inside a function, but throw statements are written in the function header

Which of these is a checked exception?

• OutOfMemoryError

• StackOverflowError

• ArithmeticException

• IOException

Which of these is caused by integer division by zero?

• ArithmeticException

• ArrayIndexOutOfBoundsException

• MathException

• DivisionByZeroException

If String s = "abc", what is the value of s.charAt(2)?

• a

• b

• c

• This command will throw a StringIndexOutOfBoundsException.

If String s = "abc", what is the value of s.charAt(3)?

• a

• b

• c

• This command will throw a StringIndexOutOfBoundsException.

If sc = new Scanner(System.in) and x = sc.nextInt(), which of these is thrown if the user inputs the String "x"?

• NullPointerException

• StringIndexOutOfBoundsException

• InputMismatchException

• IllegalArgumentException