Increment specific value of element in a 2d array JS

Question

How can I create the starting positon on a coordinate plot and update (increment) the x value? Initially, position was given values of 2 and 5 , but for testing purposes, I'd just like to update the x value by 1, but am getting the same values returned?

function boardCreate(rows, columns) {
    for (let x = 0; x < rows; x++) {
        for (let y = 0; y < columns; y++) {
            boardCell(x, y); 
        }
    }
}

function boardCell(x, y) {
    board[x] = board[x] || [];
    board[x][y] = x + " " + y;
}

var board = [];
boardCreate(10, 10);

let position = board[2][5];

function incrementX(position) {
    position[1] = position[1] + 1;
    return position;
}

incrementX(position);

console.log(position);

Answer 1

If I understand correctly, you need to increment the board coordinates based on the x and y values of the current position - this can be achieved by:

1. extracting the x and y values at the specified position

   const [x, y] = position.split(' ');

2. incrementing x by one:

   const nextX = Number.parseInt(x) + 1;

3. reading the new position value from new x value and exisiting y

   return board[nextX][y]

Hope this helps!

 function boardCreate(rows, columns) { for (let x = 0; x < rows; x++) { for (let y = 0; y < columns; y++) { boardCell(x, y); } } } function boardCell(x, y) { board[x] = board[x] || []; board[x][y] = x + " " + y; } var board = []; boardCreate(10, 10); let position = board[2][5]; function incrementX(position) { /* Ensure valid position specified before attempting increment */ if (!position) { return; } /* Read x,y coordinates from array value */ const [x, y] = position.split(' '); /* Parse x to number and increment it */ const nextX = Number.parseInt(x) + 1; if (nextX >= board.length) { console.error(`next x: ${ nextX } out of bounds`); return; } /* Look up board value at next x, and same y coordinate */ return board[nextX][y] } console.log(position); /* Testing */ let p = incrementX(position); for (let i = 0; i < 10; i++) { p = incrementX(p); console.log(p); }