I instantiated a 2D array with the size 10x10, all values are set to false. I want some of the cells to carry the value true, best case would be a random assignation.
But if I set the value of a cell to true using array[x][y] = true;, all cells with the given y value are set to true.
Example:
Input:
x = 1
y = 2
Output:
[
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false],
[false, false, true, false, false, false, false, false, false, false]
]
Any idea, why this is happening? I simply don't get it. Find my code below:
// define board size
let boardSize = [10, 10];
// create a 2D array with size 10x10 and all values false
let currentBoard = Array(boardSize[0]).fill(Array(boardSize[1]).fill(false));
// fill 3 random cells with value true
for(let i = 0; i < 3; i++){
let x = Math.floor(Math.random() * boardSize[0]);
let y = Math.floor(Math.random() * boardSize[1]);
currentBoard[x][y] = true; // this line sets the value of every x at position y to true, not just x/y
console.log(x + '/' + y); // x and y have distinct values
}
console.log(currentBoard);The problem is that the second Array.fill just refrences itself over and over again. You can fix that if you replace it with this:
let currentBoard = Array(boardSize[0]).fill([]).map(() => Array(boardSize[1]).fill(false));