Exercise Answers¶
Question 1:¶
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | public class QuestionOne { public static void main(String[] args) { double X; short Y = 10; X = Y; System.out.println(X); long Z; int F = 1234567; Z = F; System.out.println(Z); } } |
Output
10.0
1234567
Question 2:¶
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | public class QuestionTwo { public static void main(String[] args) { double X = 12345.54321789; // Show X as a double System.out.println("X as a double: " + X); // Show X as a float System.out.println("X as a float: " + (float) X); // Show X as an integer System.out.println("X as an integer: " + (int) X); // Show X as a byte System.out.println("X as a byte: " + (byte) X); } } |
Output
X as a double: 12345.54321789
X as a float: 12345.543
X as an integer: 12345
X as a byte: 57
Note
It would be good to notice that the accuracy of X drops as the cast goes to a smaller sized data type.
Question 3:¶
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | public class QuestionThree { public static void main(String[] args) { int X = 5 + 2; int Y = 20 / 2; int Z = 10 % 3; System.out.println("X = " + X + " Y = " + Y + " Z = " + Z); X %= 2; Y /= 5; Z *= 2; System.out.println("X = " + X + " Y = " + Y + " Z = " + Z); System.out.println("(X == 2) = " + (X == 2) + " (Y > 1) = " + (Y > 1) + " (Z <= 5) = " + (Z <= 5)); System.out.println("(5 > 2) && (2 > 2) = " + ((5 > 2) && (2 > 2))); System.out.println("(5 <= 5) || (2 == 2) = " + ((5 <= 5) || (2 == 2))); System.out.println("!(5 <= 6) || (2 == 2) && (3 > 3) = " + (!(5 <= 6) || (2 == 2) && (3 > 3))); } } |
Output
X = 7 Y = 10 Z = 1
X = 1 Y = 2 Z = 2
(X == 2) = false (Y > 1) = true (Z <= 5) = true
(5 > 2) && (2 > 2) = false
(5 <= 5) || (2 == 2) = true
!(5 <= 6) || (2 == 2) && (3 > 3) = false
Challenge Question¶
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | /* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package com.edu.unit3; import java.util.Scanner; /** * * @author james */ public class ChallengeQuestion { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.print("Enter purchase amount: $"); double purchaseAmount = input.nextDouble(); double tax = purchaseAmount * 0.13; System.out.println("Sales tax is: $" + (int)(tax * 100) / 100.0); } } |
Output
Enter purchase amount: $299.99
Sales Tax is: $38.99