Think of a chessboard.

let board = new Array(8);
for (let i = 0; i < board.length; i++) board[i] = new Array(8).fill(undefined);

board.put = function(arr, token) { ... }

board.print = function() { ... }

board.isFull = **result of a function but NOT A FUNCTION**
;

My aim is to have board.isFull as a property of board, without the round function brackets: board.isFull().

board.isFull should be a value, not a function.

Those won't work:

board.isFull = { ... }
board.isFull = return { function(...) }

But please: what will work?