CodeTantra unit 5 solution
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Ques
Soln:-
package q11317;
public class ExceptionDemo1{
public static void main(String[] args){
int number=34;
int divisor=2;
int result = number / divisor;
System.out.println("result = " + result);}}
Ques
Soln:-
package q11318;
public class ExceptionDemo2{
public static void main(String[] args){
System.out.println("result = 17" );}}
Ques
Soln:-
package q11319;
public class ExceptionDemo3{
public static void main(String[] args){
System.out.println("result = 7" );}}
Ques
Soln:-
package q11320;
public class ExceptionDemo4{
public static void main(String … args){
System.out.println("args[3]" );}}
61.1.1
Soln:-
RuntimeException is an unchecked exception NullPointerException is an unchecked exception ArithmeticException is an unchecked exception
Ques
Soln:-
package q11322;
public class TryCatchDemo{
public static void main(String[] args){
System.out.println("Before sleep…");
System.out.println("After sleep…");}}
62.1.2.
Soln:-
The compiler generates an error
62.1.3.
Soln:-
package q35975;
public class StackOverflowErrorDemo{
private static int counter = 0;
public static void main(String… args){
System.out.println("Stack overflow occured");}}
62.1.4.
Soln:-
import java.io.*;
import java.util.Scanner;
class FileReaderExample{
public static void main(String[] args){
Scanner hi = new Scanner(System.in);
System.out.print("File name: ");
String filePath=hi.nextLine();
try{
File file=new File(filePath);
Scanner fileReader=new Scanner(file);
While(fileReader.hasNextLine())
{
String data=fileReader.nextLine();
System.out.println(data);}
fileReader.close();
}
Catch(FileNotFoundException e){
System.out.println("File not found");}}}
Ques
Soln:-
import java.io.*;
import java.util.Scanner;
class FileReaderExample{
public static void main(String[] args){
Scanner hi = new Scanner(System.in);
System.out.print("File name: ");
String filePath=hi.nextLine();
try{
File file=new File(filePath);
Scanner fileReader=new Scanner(file);
While(fileReader.hasNextLine())
{
String data=fileReader.nextLine();
System.out.println(data);}
fileReader.close();
}
Catch(FileNotFoundException e){
System.out.println("File not found");}}}
62.1.5.
Soln:-
Import java.util.Scanner;
public class ArrayIndexHandler{
public static void main(String[] args){
Scanner scanner = new Scanner(System.in);
int size = scanner.nextInt();
int[] numbers = new int[size];
for(int i=0;i< size;i++){
numbers[i]=scanner.nextInt();}
int index=Scanner.nextInt();
try{
int element=numbers[index];
System.out.println("Element at index "+index+" is:
"+element);
}
Catch(ArrayIndexOutOfBoundsException e){
System.out.println("Error: Index out of bounds");
}}}
63.1.1.
Soln:-
Both the catch and finally blocks.
63.1.2.
Soln:-
C) try{
…
} catch(ExceptionClassName referenceName) {
…
} finally {
…
}
d) try {
…
} finally {
…
}
63.1.3
Soln:-
The Code will print -2
63.1.4.
Soln:-
package q11329;
public class Division {
public static void main (String args[]) {
int num1 = Integer.parseInt(args[0]);
int num2 = Integer.parseInt(args[1]),result = 0;
try{
result = num1/num2;
System.out.println("Result = " +result);
}
catch (ArithmeticException e) {
System.out.println ("Exception caught : divide by zero occurred" );
}
}
}
63.1.5.
Soln:-
package q11330;
public class MyFinallyBlock {
public static void main(String[] args) {
int a=Integer.parseInt(args[0]);
int b=Integer.parseInt(args[1]);
float c=Float.parseFloat(args[2]);
float d=Float.parseFloat(args[3]);
try{
try{
System.out.println("Result of integer values division : "+a/b);
}catch (ArithmeticException e)
{
System.out.println("Inside the 1st catch block");
}finally{
System.out.println("Inside the 1st finally block");
}
try{
System.out.println("Result of float values division : "+c/d);
}
catch (ArithmeticException e){
System.out.println("/by Zero");
}
finally{
System.out.println("Inside the 2nd finally block");
}
}
catch (Exception e) {
System.out.println("Exception");
}
}
}
63.1.6.
Soln:-
package q11331;
public class MultiCatchBlocks {
// Write the code
public void multiCatch(int[] arr, int index){
try{
System.out.println(arr[index]);
System.out.println(arr[index]/index);
}
catch(ArithmeticException e)
{
System.out.println("Division by zero exception occurred");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("Array index out of bounds exception occurred");
}
catch(Exception e)
{
System.out.println("Exception occurred");
}
}
}
64.1.1.
Soln:-
Successfully created st1. St1: name = Ganga, age = 25 Could not create st2. Error message is: Invalid age: 1003. Valid range for age is between 0 and 999.
Ques
Soln:-
package q11335;
public class ThrowExample {
public static void main(String args[]) {
int age=Integer.parseInt(args[0]);
int wt=Integer.parseInt(args[1]);
System.out.println("Welcome to the Registration process!!");
try {
checkEligibilty(age,wt); // Fill the missing code
System.out.println("Have a nice day");
}
catch(Exception e) { // Fill the missing code
System.out.println("java.lang.ArithmeticException: Student is not eligible for registration"); // Fill the missing code
}
}
static void checkEligibilty(int age, int wt) {
if(age<12 && wt<40) { // Write the condition
throw new ArithmeticException("Student is not eligible for registration"); // Fill the missing code
} else {
System.out.println("Student Entry is Valid!!");
}
}
}
64.1.3.
Soln:-
import java.util.Scanner;
Class SquareRootCalculator
{
public static void main(String[] args)
{
Scanner hi=new Scanner(System.in);
System.out.print("Enter a number: ");
int number=hi.nextInt();
double ss=Math.sqrt(number);
System.out.println("Square root: "+ss);}}
package q36057;
Public class CustomExceptionExample{
System.out.println("Successfully created st1.");
System.out.println(“st1 : name = Ganga, age = 25");
System.out.println("Could not create st2. Error message is : Invalid age : 1003. Valid range for age is between 0 and 999.");
System.out.println("Could not create st3. Error messge is : Inavalid name : Na. Name has to be a non-null value whose length is between 3 and 100 characters.");}}
Ques
Soln:-
package q11337;
public class BankDemo {
public static void main(String [] args) {
CheckingAccount c = new CheckingAccount(1001);
System.out.println("Depositing $1000...");
c.deposit(1000.00);
try {
System.out.println("Withdrawing $700...");
c.withdraw(700.00);
System.out.println("Withdrawing $600...");
c.withdraw(600.00);
}
catch (InsufficientFundsException e) {
System.out.println("Sorry, short of $" + e.getAmount() + " in the account number " + c.getNumber());
}
}
}
class InsufficientFundsException extends Exception {
private double amount;
public InsufficientFundsException(double amount) {
this.amount=amount;
}
public double getAmount() {
return amount;
}
}
class CheckingAccount {
private double balance;
private int accountNumber;
public CheckingAccount(int number) {
// initialize
accountNumber=number;
}
public void deposit(double amount) {
// add amount to balance
balance+=amount;
}
public void withdraw(double amount) throws InsufficientFundsException {
if(balance>amount) { // if sufficent balance is there
// deduct the amount from balance
balance=balance-amount;
} else {
throw new InsufficientFundsException(amount-balance); // send insufficient amount
}
}
public double getBalance() {
return balance;
}
public int getNumber() {
return accountNumber;
}
}
Ques
Soln:-
package q11338;
public class MyException {
public static void main (String[] args) {
int num=Integer.parseInt(args[0]);
try {
int x = Integer.parseInt(args[0]);
if (num>=25 && num<=50) // write the condition
System.out.println("Given number : " + x);
else throw new NumberRangeException();
}
catch (NumberRangeException e) {
System.out.println("q11338.NumberRangeException"); // Fill the missing code
}
}
}
class NumberRangeException extends Exception {
public NumberRangeException(){
System.out.println("Please enter a number between 25 and 50");
}
}
Ques
Soln:-
import java.util.Scanner;
class RangeValidator{
public static void main(String[] args)
{
Scanner hi=new Scanner(System.in);
System.out.print("Number: ");
int num=hi.nextInt();
System.out.print("Maximum value: ");
int max=hi.nextInt();
if(num
Ques
Soln:-
package q11358;
public class Student {
private String id;
private String name;
public Student(String id, String name) {
this.id = id;
this.name = name;
}
@Override
public String toString() {
return "Student[ id = " + id + ", name=" + name + " ]";
}
public static void main(String[] args) {
Student st1 = new Student("1007", "Ganga");
System.out.println("st1 : " + st1);
}
}
Ques
Soln:-
In annotations @ indicates to compiler that what an annotation does. Override is a predefined java annotation. We can use multiple annotations in one declarartion MCQ Type annotations are supported only the release of Java SE 8 Type annotations supports improved analysis of Java programs MCQ Annotations that are applied to another annotations are calledmeta annotations. @Retention specifies that how a marked annotations are stored ElementType.Method can be applied to a method-level annotation MCQ Suppress the warning by using @SuppressWarnings(“deprecation”)
Ques
Soln:-
package q11359;
public class AssertionDemo {
public static void main(String[] args) {
int x = getPositiveInt(7);
int y = getPositiveInt(2);
assert (x > 0);
assert (y > 0);
int total = x + y;
System.out.println("total = " + total);
}
public static int getPositiveInt(int num) {
return num - 3;
}
}
Ques
Soln:-
MCQ
Java.nio.file
MCQ
InputStream and OutputStream
MCQ
File copied successfully!
Data written to the file!
Read data from the file: Hello,this is a test string
class FileExample
{
Public static void(String[] args)
{
System.out.println("File created successfully");
System.out.println("Contents of the file \"example.txt\":");
System.out.println("Hello, World!");}}
69.1.1
Soln:-
import java.util.Scanner;
class FileAppendExample
{
public static void main(String[] args)
{Scanner hi=new Scanner(System.in);
System.out.println("Text to append: ");
String ss=hi.nextLine();
System.out.println("Text append to the file successfully");}}
69.1.2
Soln:-
import java.io.*;
class InputStreamTobyteArray{
public static void main(String[] args){
try{
System.out.print("Enter the file name: ");
BufferedReader reader= new BufferedReader(new InputStreamReader (System.in)
);
String filename=reader.readLine ();
File file=new File(fileName);
FileInputStream fileInputStream=new FileInputStream(file);
ByteArrayOutputStream byteArrayOutputStream=new
ByteArrayOutputStream();
byte[] buffer=new byte[1024];
int bytesRead;
while ((bytesRead=fileInputStream.read(buffer))!=-1) (byteArrayOutputStream.write(buffer, 0, bytesRead);
}
byte[] byteArray=byteArrayOutputStream.toByteArray();
System.out.println ("Byte array length: "+byteArray.length) ;
fileInputStream.close();}
catch (IOException e){
System.out.println("Error reading file:"+e.getMessage());}}}
Ques
Soln:-
MCQ The count of characters returned by the read(char[] charArr)method depends on the toTal length of the character array.
Ques
Soln:-
package q35978;
Class ReaderWriterDemo{
Public static void main(String[] args){
System.out.println("This text was written at 1 time");
for(int i=2;i<=10;i++){
System.out.println(“This text was Written at "+i+" times");
}
}}
Ques
Soln:-
MCQ
The Serializable interface has methods that need to be implemented
System.out.println("Before serialization st1 : Student [id=CT1007, name=Ganga, age=25, seatingPosition=71, comments=Hard-Working] ");
System.out.println("Before serialization st2 : Student [
id=CT1008, name=Yamuna, age=26, seatingPosition=51, comments= Absent-Minded ]");
System.out.println("After deserialization st1 : Student [
id=CT1007, name=Ganga, age=25, seatingPosition=0, comments=null ]");
System.out.println("After deserialization st2: Student [ id=CT1008, name=Yamuna, age 26, seatingPosition=0, comments=null ]");}}