Question

1. Write a Java program that prompts the user to enter three integer numbers. Calculate and print the average of the numbers.
2. Write a Java program that uses a for loop to print the odd numbers from 1 to 20. Print one number per line in the command line window.
3. Write a program which asks the user to input the size of potatoe fries she would like to purchase, and based on the size, it will tell her a price. The prices are as follows:
1
Small
$ 5
2
Medium
$ 10
3
Large
$ 15
The user should type in the number 1, 2 or 3 in order to select the size. Ensure that you instruct the user to do so in your text input dialog box.
4. The average age to obtain a driver’s licence is 18. Write a Java program where the user enters his / her age. If the age is greater than and equal to 18 the program must display using JOptionPane the following message, “you are old enough to apply for a driver’s licence”, else display the following message, “you are not old enough to apply for a driver’s licence”.

Answer 1

Average.java

import java.util.Scanner;

public class Average {
   public static void main(String[] args) {
       // Scanner class object to get the input from user
       Scanner sc=new Scanner(System.in);
       System.out.println("Enter three integer numbers:");
       // get three integer numbers from user
       int num1=sc.nextInt();
       int num2=sc.nextInt();
       int num3=sc.nextInt();
       // calculate average
       double average=(num1+num2+num3)/3;
       // print average of three numbers
       System.out.printf("Average of three numbers is: %.2f",average);
       sc.close(); // close Scanner object
   }
}

Output

*************************************************************

*************************************************************

OddNumbers.java

public class OddNumbers {
   public static void main(String[] args) {
       System.out.println("Odd numbers from 1 to 20 are:");
       for(int i=1;i<=20;i++)
           // check number is odd or not
           if(i%2!=0)
               // print the number
               System.out.println(i);
   }
}

Output

*************************************************************

*************************************************************

PotatoeFries.java

import javax.swing.JOptionPane;

public class PotatoeFries {
   public static void main(String[] args) {
       // accept input from input dialog box
       int size=Integer.parseInt(JOptionPane.showInputDialog("Enter the size of potatoe fries like to purchase:"));
       if(size==1) {
           System.out.println(size);
           System.out.println("Small");
           System.out.println("$5");
       }else
           if(size==2) {
               System.out.println(size);
               System.out.println("Medium");
               System.out.println("$10");
           }else
               if(size==3) {
                   System.out.println(size);
                   System.out.println("Large");
                   System.out.println("$15");
               }else
                   System.out.println("Wrong input...!!!");
   }
}

Output

*************************************************************

*************************************************************

DriverLicence.java

import java.util.Scanner;

import javax.swing.JOptionPane;

public class DriverLicence {
   public static void main(String[] args) {
       // Scanner class object to get the input from user
       Scanner sc=new Scanner(System.in);
       System.out.print("Enter his/her age: ");
       int age=sc.nextInt(); // get age from user
       // check age is greater than 18 or not
       if(age>=18)
           // show message using JOptionPane message box
           JOptionPane.showMessageDialog(null, "You are old enough to apply for a driver’s licence");
       else
           JOptionPane.showMessageDialog(null, "You are not old enough to apply for a driver’s licence");
       sc.close(); // close scanner object
   }
}

Output