IST140Unit3PracticeQuizModel.java

package unit3practicequizmodel;
import java.util.Scanner;
/**
 *
 * @author marcfriedenberg
 */
    public class Unit3PracticeQuizModel {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);
        /*1. Write a Java snippet to request a value of type double from the user (call it temp).
        This is the value of a sample of water. Use the following rules to decide its state
        and output the result.
        If temp is 32.0 or less, output "Solid"; if it is 212.0 or higher, output "Gas";
        otherwise output "Liquid".
        */

        System.out.print("Please enter a temperature: ");
        double temp = scnr.nextDouble();
        if (temp <= 32.0)
        {
            System.out.println("Solid");
        }
        else if (temp >= 212.0)
        {
            System.out.println("Gas");
        }
        else
        {
            System.out.println("Liquid");
        }

/*2. Examine the expression below. What is the value of the boolean variable myBoolean?

boolean myBoolean = (100 > 250 || 110 > 100) && 50 >= 250;
*/

        /*
        This evaluates to false. You can verify this by running
        System.out.println((100 > 250 || 110 > 100) && 50 >= 250)
        in NetBeans, and it will print "false."

        If we break the expression into smaller pieces, we could start with:

           (false || true) && false

        Which further decomposes to:

        true && false

        This returns false. It's the same as asking "Is it true that 
        both 'true' and 'false' are 'true'?" It is not, which is why the 
        myBoolean evaluates to false.
        */

/*3. Write a Java snippet to request a value of type integer from the user (call it selection).
Validate that the user has entered an integer. If so read it, then use a switch-case statement to 
branch on the value using the following rules. If the value equals 1, output "First"; 
if the value equals 2, output "Second", otherwise output "Invalid entry". 
*/

        System.out.print("Please enter an integer: ");
        if (scnr.hasNextInt())
        {
            int selection = scnr.nextInt();
            switch (selection)
            {
                case 1: System.out.println("First"); break;
                case 2: System.out.println("Second"); break;
                default: System.out.println("Invalid entry"); break;
            }
        }
        else
        {
            System.out.println("Invalid entry");
        }

/* 4. Write a Java snippet to determine the topic in IST 140. 
Ask the user to enter the day of the week: Monday, Wednesday or Friday. 
Ask the user to enter the number of the week: 7, 8, 9, or 10.
Validate that the user entered an integer. If invalid, set integer flag to true.
If valid entries: 
If it is Monday, Wednesday or Friday, and it is week 7 or 8, output “The topic is loops.”
If it is Monday, Wednesday or Friday, and it is week 9 or 10, output “The topic is arrays.”
Else print a message “Invalid entry.”

*/
    
        System.out.print("Please enter a day of the week (Monday, Wednesday, or Friday): ");
        String dayOfWeek = scnr.nextLine();
        
        /*I'm not sure we've covered the necessity of the line below. Without it,
        both prompts will be displayed to the user back-to-back, without waiting
        for user input in between. It would work, but wouldn't look great. The problem 
        is that the nextInt() call below doesn't capture the \n that the user entered
        when they entered the day of the week. So, we need to capture it here, and just
        stuff it in a variable that we'll never actually use. "Foo" is a common
        variable name for just this sort of thing. It's a play on FUBAR, a military
        term you can Google if you're interested. */
        String foo = scnr.nextLine();
        
        System.out.print("Enter the number of the week (7, 8, 9, or 10): ");
        if (scnr.hasNextInt()){
            int numberOfWeek = scnr.nextInt();
            if (dayOfWeek.equals("Monday") || dayOfWeek.equals("Wednesday") || dayOfWeek.equals("Friday")) 
            {
                switch (numberOfWeek)
                {
                    case 7: System.out.println("The topic is loops."); break;
                    case 8: System.out.println("The topic is loops."); break;
                    case 9: System.out.println("The topic is arrays."); break;
                    case 10: System.out.println("The topic is arrays."); break;
                    default: System.out.println("Invalid entry."); break;
                }
             
            }
            else
            {
                //user has entered a day other than Monday, Wednesday, or Friday
                System.out.println("Invalid entry.");
            }
        }
        else
        {
            //user has not entered an integer
            boolean isInteger = false;
            System.out.println("Invalid entry.");
        }
    }
    
}