Visualizing Directional Exploration of a Matrix

index.js

/*
  Visualizing Directional Exploration of a Matrix
  
  A little homework for myself.  I find it difficult at times to visualize a
  matrix when it's represented as an array.  Specifically when I'm setting up
  some array of directions for BFS style matrix searching - I always have to
  think very about the array I setup for exploring different directions.

  So, I wrote this - to prove it out for myself and run it in a browser console.
  Thanks Chroms for your awesome console.log display :)
*/

let directions = [[0,0], [0, 1], [1, 1], [1,0], [1, -1], [0, -1], [-1,-1], [-1, 0], [-1, 1]];
let testDirection = (x, y) => {
  let grid = [[0,0,0], [0,0,0], [0,0,0]];
  let i = 1;
  let j = 1;
  grid[i+x][j+y] = 1;
  console.log(grid);
}
for (const [index, [x,y]] of directions.entries()) {
  console.log(`Index: ${index}, x: ${x} y: ${y}`);
  testDirection(x, y);
}