Question

How would I code this method in Java using a scanner?

Begin by asking how many spaces the row should be with a prompt using System.out.print like the following, with 40 as the maximally allowed number of spaces: (user input shown bold)

Please enter the number of spaces for the game (1-40): eight

To do this, use the promptNumberReadLine method that you will write, described on the back page. If the user does not type a number in the correct range, that method will prompt them in this way:

That was not a valid number! Please try again. Please enter the number of spaces for the game (1-40): 8

public static int promptNumberReadLine(Scanner s, String prompt, int max) Print the prompt using System.out.print(…). If the next piece of information in the Scanner represents an integer which is at least 1 and at most max, return the number, but make sure the Scanner also reads in the rest of the line before returning. Otherwise (if the next piece of information doesn’t represent the above requirements), read in the rest of the line, print the line That was not a valid number! Please try again. and repeat the process described in this box.

Answer 1

" but make sure the Scanner also reads in the rest of the line before returning" Its not clear what this mean.Can you provide some examples for this. If its to just read the line, I have added a line for that, else provide example, I will implement. Also "eight" is a valid condition or invalid condition ? specify that too.

import java.util.Scanner;

public class ScannerTest
{ public static int promptNumberReadLine(Scanner s, String prompt, int max)
{
    int data = -1;
    String line;
    boolean isExit = false;
    do
    {
            System.out.print(prompt);
            String strData = s.next();
        try
        {
            // Read input from user
            data = Integer.parseInt(strData);
            // Validate input
            if (data > 0 && data <= max)
            {
                // Flag for exitig loop
                isExit = true;
                // read rest of the line
                line = s.nextLine();
            } else
            {
                // message to user
                System.out.println("That was not a valid number! Please try again.");
            }
        }
        catch (NumberFormatException e)
        {
            // message to user
            System.out.println("That was not a valid number! Please try again.");
        }
    } while (!isExit) ;
    // return value
    return data;
}
    public static void main(String [] args)
    {
        Scanner s = new Scanner(System.in);
        String prompt = "Please enter the number of spaces for the game (1-40): ";
        int data = promptNumberReadLine(s,prompt,40);
    }
}

import java.util.Scanner; 2 4 @ 5 public class ScannerTest { public static int promptNumberReadLine(Scanner s, String prompt, int max) { int data = -1; String line; boolean isExit = false; do 10 { System.out.println(prompt); String strData = s.next(); try // Read input from user data = Integer.parseInt(strData);|| // Validate input if (data > 0 && data <= max) // Flag for exitig loop isExit = true; // read rest of the line line = s.nextLine(); } else // message to user System.out.println("That was not a valid number! Please try again.");

catch (NumberFormatException e) 31 // message to user System.out.println("That was not a valid number! Please try again."); 36 37 38 } while (!isExit) ; // return value return data; } 40 public static void main(String [] args) { Scanner s = new Scanner(System.in); String prompt = "Please enter the number of spaces for the game (1-40)"; int data = promptNumberReadLine(s, prompt, max: 40); } 42 44 45 }

Please enter the number of spaces for the game (1-40): 56 That was not a valid number! Please try again. Please enter the number of spaces for the game (1-40): 48 That was not a valid number! Please try again. Please enter the number of spaces for the game (1-40): eight That was not a valid number! Please try again. Please enter the number of spaces for the game (1-40): & Process finished with exit code o