These snippets build a grid with HTML and associate the cells in a 2-dimensional array

playing_with_grids.js

// Inspired by @kokokonotsu
///  https://github.com/kokokonotsu/Cells-and-Grids

const
  gridContainer = 'body',  // selector for our HTML grid
  columnCount = 26,        // number of columns
  rowCount = 20;           // number of rows


// Generate the grid
function makeGrid(x,y) {
  const HTMLgrid = ('<div class="row">' + '<div class="cell"></div>'.repeat(x) + '</div>').repeat(y);
  document.querySelector(gridContainer).innerHTML = HTMLgrid;
}


// Build a 2-dimensional array associated with the grid
function setArray() {
  const
    rows = Array
      .from(document.querySelectorAll(`${gridContainer} .row`))
      .reverse(), ///  dom elements are loaded from top to bottom, which inverts our y-axis
    x = rows[0].children.length,
    y = rows.length,
    thisArray = [];

  for (let i=0; i<x; i++) { ///  magic that associates each cell in the 2D Array
    thisArray[i] = new Array(y);
    for (let j=0; j<y; j++) {
      thisArray[i][j] = rows[j].children[i];
    }
  }

  return thisArray;
}


// let's try it out!
makeGrid(columnCount, rowCount);
let cellsArray = setArray();