Chapter 12 Exercises
Exercise 1. Division by zero. Write a program that asks the user for two numbers and tries to divide the first by the second. Handle the ArithmeticException in case of division by zero.
Solution:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter the first number:");
int num1 = scanner.nextInt();
System.out.println("Enter the second number:");
int num2 = scanner.nextInt();
try {
int result = num1 / num2;
System.out.println("The result is: " + result);
} catch (ArithmeticException e) {
System.out.println("Error: Cannot divide by zero.");
}
scanner.close();
}
}Exercise 2. Handling NumberFormatException: Write a program that asks the user for an integer and tries to convert it. Handle the NumberFormatException in case the format is invalid. Once you’ve completed the exercise, try inserting a decimal number to see what happens.
Solution:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter an integer:");
String input = scanner.nextLine();
try {
int number = Integer.parseInt(input);
System.out.println("The entered number is: " + number);
} catch (NumberFormatException e) {
System.out.println("Error: Invalid number format.");
}
scanner.close();
}
}Exercise 3. Index out of range in an array. Write a program that creates an array of 5 elements and tries to access a position out of range. Handle the ArrayIndexOutOfBoundsException
Solution:
public class Main {
public static void main(String[] args) {
int[] array = {1, 2, 3, 4, 5};
try {
int value = array[10];
System.out.println("The value is: " + value);
} catch (ArrayIndexOutOfBoundsException e) {
System.out.println("Error: Index out of range.");
}
}
}Exercise 4. Invalid arithmetic operation. Write a program that asks the user for two numbers and subtracts them. Handle the ArithmeticException if the operation is invalid for some reason (e.g., subtraction of extremely large values).
Solution:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter the first number:");
long num1 = scanner.nextLong();
System.out.println("Enter the second number:");
long num2 = scanner.nextLong();
try {
long result = Math.subtractExact(num1, num2);
System.out.println("The result is: " + result);
} catch (ArithmeticException e) {
System.out.println("Error: Invalid arithmetic operation.");
}
scanner.close();
}
}Exercise 5. String concatenation. Write a program that tries to concatenate a very large number of strings, causing an OutOfMemoryError. Handle the exception.
Solution:
public class Main {
public static void main(String[] args) {
try {
String str = "";
for (int i = 0; i < Integer.MAX_VALUE; i++) {
str += "a";
}
} catch (OutOfMemoryError e) {
System.out.println("Error: Insufficient memory for the operation.");
}
}
}