## Question: Javascript 2d array select around from single point

Say I have a 15x15 2d array

` [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, A, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] `

See the character A? at y:9 and x:4 (index starts with 0). What I want to do here is to javascript error update the array where I select or update the 0s around the A to, say, asterisk (*).

For an example, lets say I want 0s around the A as far as 3 indexes to be updated as *

` [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, *, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, *, *, *, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, *, *, *, *, *, 0, 0, 0, 0, 0, 0, 0, 0], [0, *, *, *, A, *, *, *, 0, 0, 0, 0, 0, 0, 0], [0, 0, *, *, *, *, *, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, *, *, *, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, *, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] `

What is the most efficient way to achieve this?

EDIT What I've tried:

`var s_length = 4, coordinate_y_x = [9, 4] for (let i1 = 0; i1 < s_length; i1++) { for (let i = 0; i < s_length; i++) { if (map[coordinate_y_x[0] - i][coordinate_y_x[1]] != undefined) map[coordinate_y_x[0] - i][coordinate_y_x[1]] = 1 if (map[coordinate_y_x[0]][coordinate_y_x[1] - i]!= undefined) map[coordinate_y_x[0]][coordinate_y_x[1] - i] = 1 } for (let i = s_length; i > 0; i--) { console.log("loop2"); if (map[coordinate_y_x[0] + i][coordinate_y_x[1]]!= undefined) map[coordinate_y_x[0] + i][coordinate_y_x[1]] = 1 if (map[coordinate_y_x[0]][coordinate_y_x[1] + i]!= undefined) map[coordinate_y_x[0]][coordinate_y_x[1] + i] = 1 } } `

I managed to change what's left, right, top, and bottom from this code with given point and length, but javascript error I can't seem to figure out how to do the rest (between directions)

` [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 1, 1, 1, A, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] `