Exam 12: Exception Handling

The ____ class comprises less serious errors that represent unusual conditions that arise while a program is running and from which the program can recover.

When an exception is a checked exception, client programmers are forced to deal with the possibility that an exception will be thrown.

import java.util.*; public class DivisionMistakeCaught3 {     public static void main(String[] args)     {        Scanner input = new Scanner(System.in);        int numerator, denominator, result;        try        {           System.out.print("Enter numerator >> ");           numerator = input.nextInt();           System.out.print("Enter denominator >> ");           denominator = input.nextInt();           result = numerator / denominator;           System.out.println(numerator + " / " + denominator + " = " + result);        }        catch(ArithmeticException mistake)        {           System.out.println(mistake.getMessage());        }        catch(InputMismatchException mistake)        {           System.out.println("Wrong data type");        }       } } Using the above code, describe what will happen if a user enters two usable integers. What will happen if a user enters an invalid noninteger value? What will happen if the user enters 0 for the denominator?

If a method throws an exception that it will not catch but that will be caught by a different method, you must also use the keyword ____ followed by an Exception type in the method header.

The example code above uses the getMessage() method. Explain how the getMessage() method makes error message generation more specific to the error encountered.

What advantages does object-oriented exception handling provide?

The ____ option must be used when running a program in order to see the results of assert statements.

A(n) ____ is a Java language feature that can help you detect logic errors that do not cause a program to terminate, but nevertheless produce incorrect results.

The figures above show the HighBalanceException and CustomerAccount classes. Explain what is involved in creating your own throwable Exception s. Explain what will happen if the CustomerAccount throws a HighBalanceException .

import java.util.*; import java.util.Scanner; public class AssertionExample {     public static void main( String args[] )    {        Scanner scanner = new Scanner( System.in );        System.out.print( "Enter a number between 0 and 20: " );        int value = scanner.nextInt();        ---Code here---        "Invalid number: " + value;        System.out.printf( "You have entered %d\n", value );    } } In the code above, when the user enters the number, the scanner.nextInt() method reads the number from the command line. In the blank line provided, create an assert statement that determines whether the entered  number is within the valid range (between 0 and 20). If the user entered a number that is out of range, then the "Invalid number" error should occur.

The figure above shows a call stack. Explain how a call stack works.

The keyword catch followed by an Exception type in the method header is used when a method throws an exception that it will not catch but that will be caught by a different method.

A catch block is a method that can be called directly and takes an argument that is some type of exception.

What are unchecked exceptions? Give an example.

You can place as many statements as you need within a try block, and you can catch as many exceptions as you want.