User input into array

[Ron Ingram]

Hello,

Im working on the magic squares assignment and the tester asks the user to input values on a single line to be used for the magic square class. My problem is how do I take values given on one line and seperate them into an array or 2D array?

This is an example user input:

Enter a sequence of integers, followed by Q:
16 3 2 13 5 10 11 8 9 6 7 12 4 15 14 1
Q

I'm trying to take the values and insert them into a StringBuilder then back toString() which does a good job seperating them by the space, but how do I put them into an array?

Here are my classes so far

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package Ass7_MagicSquares;

import java.util.ArrayList;

/**
 *
 * @author ronald.ingram
 */
public class Square {

    int counter;
    int size;
    int i;
    int square[][];
    String s;
    String[] sep;
    StringBuilder sb = new StringBuilder();

    public void add(int a) {


        //square = new int[size][size];

        //Place the line of inputted values into a StringBuilder 
        StringBuilder sb = new StringBuilder();
        sb.append(a);
        
        s = sb.toString();
        System.out.println("StringBuilder= " + s);



        //Ensure user entered enough values to be used by the magic square test
        //Must get the square root value that is an even number, no decimals
        //The correct value from the square root of the amount of entries creates the x,y for the 2Darray
        if (size % 2 == 0) {
            System.out.println("The user entered n2 for the magic squares");
        } else {
            System.out.println("The user did not enter the correct amount");
            System.out.println("This progrom is now exiting");
            System.exit(0);

        }

    }

    public Boolean isMagic() {
        boolean b = false;



        return b;
    }
}

Here is the tester class:

public class MagicSquareChecker
{  
   public static void main(String[] args)
   {  
      Scanner in = new Scanner(System.in);
      Square sq = new Square();
      

      System.out.println("Enter a sequence of integers, followed by Q: ");
      while (in.hasNextInt())
      {
         sq.add(in.nextInt());
      }

      if(sq.isMagic())
         System.out.println("It is a magic square.");            
      else
         System.out.println("It is not a magic square.");             
   }
}

[Wouter Oet]

You can use String.split() to split the string into an array of strings. Then you'll need to parse the String to an int.

[Winston Gutkowski]

Ron Ingram wrote:Im working on the magic squares assignment and the tester asks the user to input values on a single line to be used for the magic square class. My problem is how do I take values given on one line and seperate them into an array or 2D array?

Well, as Wouter said, String.split() will create an array of the number strings for you. The problem is that it will be a one-dimensional array of String[16], and I presume that you want to convert that into an int[4][4].

My suggestion: have a look at the '/' and '%' operators, and think about what they do.

It might also be worth going through all the index values for your String[] and printing out the results.

Winston