Week 3 Homework Solutions

WeekThreeHW.java

import java.util.Scanner;

/**
 * This class contains the solutions to
 * the Week 3 homework exercises.
 */
public class WeekThreeHW {

    public static void main(String[] args) {

        /* Problem 1: Guess the number
        ---------------------------------------------
        Create a program that satisfies the following:
            - The computer has a number between 1 & 100
            - The user tries to guess it
            - The computer tells it to go higher or lower
            - If the person gets the number right, the
              computer says so
         */

        System.out.println("\nHomework Problem 1:\n"); // to separate Problems

        int num = 67; // variable holds the correct number

        Scanner userInput = new Scanner(System.in); // create a scanner object

        System.out.println("\tGuess a number from 1 to 100: "); // ask user

        String input = userInput.nextLine(); // get and store user input in string

        int guess = Integer.parseInt(input); // change string to int value

        // if the guess is greater than the correct number
        if (guess > num) {
            System.out.println("\t" + guess + " is too high! Go lower");
        }
        // if the guess is less than the correct number
        else if (guess < num) {
            System.out.println("\t" + guess + " is too low! Go higher");
        }
        // if the guess equal to the correct number
        else {
            System.out.println("\tYou guessed right! Well done :)");
        }

        /* Problem 2: Calculating Arithmetic Operations with User Input
        ---------------------------------------------------------------
        Create a program that:
            - Asks for 2 numbers
            - Executes all the arithmetic operations on those 2 numbers
              and returns them to the user.
            - Hint: Think about user data, how many variables you need,
              and what the operations are!

         Note: If you store numbers as double and use Double.parseDouble()
         it is fine too!
         */

        System.out.println("\nHomework Problem 2:\n"); // to separate Problems

        System.out.println("\tEnter first number: "); // ask user

        // we are using scanner object from before (userInput)
        String s1 = userInput.nextLine(); // get and store user input in string
        int x = Integer.parseInt(s1); // change string to int value

        System.out.println("\tEnter second number: "); // ask user

        String s2 = userInput.nextLine(); // get and store user input in string
        int y = Integer.parseInt(s2); // change string to int value

        // All arithmetic operations
        System.out.println("\t" + x + " + " + y + " = " + (x + y)); // addition
        System.out.println("\t" + x + " - " + y + " = " + (x - y)); // subtraction
        System.out.println("\t" + x + " * " + y + " = " + (x * y)); // multiplication
        System.out.println("\t" + x + " / " + y + " = " + (x / y)); // division
        System.out.println("\t" + x + " % " + y + " = " + (x % y)); // modulo

        /* Optional Problem
        --------------------

        Problem 1: Roller coaster
        Create a program that satisfies the following:
            - If I am taller than 1.5 m then print (“I can ride the roller coaster”)
            - If I am taller than 1 m and older than 15 then print (“I can ride”)
            - If there is anything else print (“I can’t ride”)
            - Hint: Think about the variables you will need

         Note: If you get height and age from user input that is fine too
         */

        System.out.println("\nOptional Problem 1:\n"); // to separate Problems

        // try changing these values to see what happens
        double height = 1.2; // in meters
        int age = 17;

        // If height is greater than 1.5 m
        if (height > 1.5) {
            System.out.println("\tI can ride the roller coaster");
        }
        // If height is greater than 1 m and older than 15
        else if (height > 1 && age > 15) {
            System.out.println("\tI can ride");
        }
        // anything else
        else {
            System.out.println("\tI can't ride");
        }

    }

}