Workshop › Minesweeper › Step 5 of 26

Neighbours

What we are doing

Almost every question in Minesweeper is about a cell's neighbours: the up to eight cells around it. Two loops over the offsets -1, 0, 1 find them, skipping the cell itself and anything off the board.

```js
// The up to 8 cells around a cell, skipping the ones that would be off the board.
function neighbors(cell) {
  const list = []
  for (let dr = -1; dr <= 1; dr++) {
    for (let dc = -1; dc <= 1; dc++) {
      if (dr === 0 && dc === 0) continue
      const row = cell.row + dr
      const col = cell.col + dc
      if (row >= 0 && row < SIZE && col >= 0 && col < SIZE) list.push(grid[row][col])
    }
  }
  return list
}
```

What it means

Two counting loops: dr (row offset) and dc (column offset) each take -1, 0 and 1.
continue skips the rest of this turn: the offset (0, 0) is the cell itself.
The bounds check keeps corner cells at 3 neighbours and edge cells at 5. Without it, grid[-1] is undefined and the next line crashes.

Your turn

Under the newGame function, leave an empty line and write the comment and neighbors. Press Run.

Skills: Loops, Arrays and objects

← Draw every frame Mines, but not under the first click →

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