Polymorphism and exception handling after-class operations

Hands-on brain: multilayer anomaly capture -1

Read the following code (Catchwho.java) to write out the results of the program run:

public class Catchwho {

public static void Main (string[] args) {

try {

try {

throw new ArrayIndexOutOfBoundsException ();

}

catch (ArrayIndexOutOfBoundsException e) {

System.out.println ("arrayindexoutofboundsexception" + "/ inner layer try-catch");

}

throw new ArithmeticException ();

}

catch (ArithmeticException e) {

System.out.println (" occurring arithmeticexception");

}

catch (ArrayIndexOutOfBoundsException e) {

System.out.println ("arrayindexoutofboundsexception" + "/ outer try-catch");

}

}

}

Program Results :

Hands-on brain: multilayer anomaly capture -2

Write The results of the Catchwho2.java program run

public class CatchWho2 {

public static void Main (string[] args) {

try {

try {

throw new ArrayIndexOutOfBoundsException ();

}

catch (ArithmeticException e) {

System.out.println ("arrayindexoutofboundsexception" + "/ inner layer try-catch");

}

throw new ArithmeticException ();

}

catch (ArithmeticException e) {

System.out.println (" occurring arithmeticexception");

}

catch (ArrayIndexOutOfBoundsException e) {

System.out.println ("arrayindexoutofboundsexception" + "/ outer try-catch");

}

}

}

Program results:

Analysis: Thefinally statement block will be executed?

Please answer these questions through the systemexitandfinally.java sample Program

public class Test {

public static void Main (string[] args)

{

try{

SYSTEM.OUT.PRINTLN ("in Main");

throw new Exception ("Exception is thrown in main");

System.exit (0);

}

catch (Exception e)

{

System.out.println (E.getmessage ());

System.exit (0);

}

Finally

{

System.out.println ("in finally");

}

}

}

Program results:

Write a program that requires the user to enter an integer at run time, representing the exam results of a course, followed by a "fail", "Pass", "Medium", "good", "excellent" conclusion.
Requires that the program be robust enough that it does not crash regardless of what the user enters.

SOURCE program code:

Import Java.util.Scanner;

Class Aexception extends Exception

{

String error;

Aexception ()

{

Error= " Please note that the requirement is The number of the input 0~100 ";

}

Public String GetError ()

{

return error;

}

}

Class Test

{

public static void Main (String args[])

{

Scanner sc = new Scanner (system.in);

System.out.println (" Please enter exam results (0~100):");

Try

{

String s = sc.nextline (); Type of read-in screen converted to type S

Getnum (s);// Determine if an exception is thrown

}

catch (Aexception e)

{

System.out.println (E.geterror ());

}

}

private static void Getnum (String s) throws Aexception

{

for (int i = s.length ();-I. >= 0;)

{

int chr = S.charat (i);

if (Chr < | | CHR > 57)

{

throw new Aexception ();

}

}

Double num = double.parsedouble (s);

if (num < 0 | | num> 100)

{

throw new Aexception ();

}

if (num>= 0 && num<= 60)

{

System.out.print (" less than lattice ");

}

else if (num >= && num <= 70)

{

System.out.print (" pass ");

}

else if (num>= && num<= 80)

{

System.out.print (" medium ");

}

else if (num >= && num <= 90)

{

System.out.print (" Liang ");

}

Else

{

System.out.print (" excellent ");

}

}

}

Question Answer:

The finally statement block executes only if the TRY statement block corresponding to finally is executed. If a try statement block is returned (return) or an exception is thrown, the finally statement block of the try will not execute

Polymorphism and exception handling after-class operations