class Solution {
  maxAreaOfIsland(matrix) {
    let biggestIslandArea = 0;
    let islandCounter = [];
    let row = matrix.length;
    let col = matrix[0].length;
    let visitedMatrix = Array(row).fill(false).map(() => Array(col).fill(false));
    for(let i=0; i<row; i++) {
        for(let j=0; j<col; j++) {
            if(matrix[i][j] === 1 && visitedMatrix[i][j] === false) {
                biggestIslandArea = visitedMatrixFiller(matrix, visitedMatrix, biggestIslandArea, i,j);
                islandCounter.push(biggestIslandArea);
                biggestIslandArea = 0;
            }
        }
    }
    console.log(islandCounter); --> This produces [4,1,5]
    return Math.max(islandCounter); --> This produces null
  }
}

function visitedMatrixFiller(matrix, visitedMatrix, biggestIslandArea, i,j) {
    const neighbors = [[i,j]];
    while(neighbors.length > 0) {
        const cell = neighbors.shift();
        let row = cell[0];
        let col = cell[1];
        if(row < 0 || row >= matrix.length || col < 0 || matrix[0].length <= col)
            continue;
        if(visitedMatrix[row][col] === true || matrix[row][col] === 0)
            continue;
        visitedMatrix[row][col] = true;
        biggestIslandArea++;

        neighbors.push([row-1, col]);
        neighbors.push([row+1, col]);
        neighbors.push([row, col-1]);
        neighbors.push([row, col+1]);
    }

    return biggestIslandArea
}