如何创建一个数组，用于存储来自连续用户输入的x，y坐标？

Question

I'm currently making a RobotArena game on Java and one of the tasks is to make an array for storing each robot in the game. For example, if the user wants 2 robots in the game... I'll have to store the 2 robots in an array (the x and y co ordinates of them) or if the user wants more Robots than just 2.

I've made a 2D array for the robot co ordinates but it only stores the latest X/Y co-ordinate of the robot in the array and doesn't store the previous robots co ordinate.

Is there a way to do this? Assigning it to a variable or putting it in a loop? Any answers will be appreciated.

This is the code I have so far, I'm new to Java, so I'm sorry if the code isn't too good.

public static class RobotArena{
    public RobotArena(int x, int y){
        int Arena[][] = new int[4][4]; //Sets the 2d array
        Arena[x][y] = '1'; //Puts 1 where the X/Y co ordinate is

        for (int[] a : Arena) { //this prints out the grid
            for (int i : a) {
                System.out.print(i + " ");
            }
            System.out.println("\n");
        }

        public static void main(String[] args) {

            Scanner s = new Scanner(System.in);
            System.out.println("How many Robots in your world?");
            int numRobots = s.nextInt();

            Robot[] allRobots = new Robot[numRobots];
            Robot.RobotArena[] allRobots2 = new Robot.RobotArena[numRobots];

            int rx, ry;

            System.out.println("Now enter position of each robot in turn (as x y) >");
            for (int ct = 0; ct<numRobots; ct++) {
                System.out.println("Enter, x y position for " + ct + "th robot: >");
                rx = s.nextInt();
                ry = s.nextInt();
                allRobots[ct] = new Robot(rx, ry);
                allRobots2[ct] = new RobotArena(rx, ry);
                allRobots[ct].printIdPosition(); 
            }       
        }
    }
}

This is the output when I add 2 robots to the game:

Co-ordinate of Robot 1 (1, 1);

0 0 0 0 
0 49 0 0 
0 0 0 0 
0 0 0 0 

When I add the 2nd robot to the game, this is the output, with co-ord (2, 2):

0 0 0 0 
0 0 0 0 
0 0 49 0 
0 0 0 0 

I want the 1st robot to be displayed in the latest grade too, but I'm not sure how to go round doing so.

Answer 1

I would rather do it this way:

• Use only one variable to initialize all robots

• Use a private member to initialize Arena

• Make a method that would set Co-ordinates

• Make a method that would print the Arena.

public static class RobotArena{
    int Arena[][] = new int[4][4];


public void setCoordinates(int x,int y){
    Arena[x][y] = '1';
}
public void printArena(){
     for (int[] a : Arena) { //this prints out the grid
        for (int i : a) {
            System.out.print(i + " ");
        }
        System.out.println("\n");
    }
}
}

    public static void main(String[] args) {

        Scanner s = new Scanner(System.in);
        System.out.println("How many Robots in your world?");
        int numRobots = s.nextInt();

       RobotArena allRobots=new RobotArena();

        int rx, ry;

        System.out.println("Now enter position of each robot in turn (as x y) >");
        for (int ct = 0; ct<numRobots; ct++) {
            System.out.println("Enter, x y position for " + ct + "th robot: >");
            rx = s.nextInt();
            ry = s.nextInt();
            allRobots.setCoordinates(rx, ry);

            //allRobots[ct].printIdPosition(); 
        }
        allRobots.printArena();
    }