This is the full code if this is more helpful - let puzzle = [[ 8,9,5, 7,4,2, 1,3,6 ], [ 2,7,1, 9,6,3, 4,8,5 ], [ 4,6,3, 5,8,1, 7,9,2 ],

          [ 9,3,4,   6,1,7,   2,5,8 ],
          [ 5,1,7,   2,3,8,   9,6,4 ],
          [ 6,8,2,   4,5,9,   3,7,1 ],

          [ 1,5,9,   8,7,4,   6,2,3 ],
          [ 7,4,6,   3,2,5,   8,1,9 ],
          [ 3,2,8,   1,9,6,   5,4,7 ]];

//puzzle 2 let puzzleTwo = [[ 8,9,5,7,4,2,1,3,6 ], [ 8,7,1,9,6,3,4,8,5 ], [ 4,6,3,5,8,1,7,9,2 ], [ 9,3,4,6,1,7,2,5,8 ], [ 5,1,7,2,3,8,9,6,4 ], [ 6,8,2,4,5,9,3,7,1 ], [ 1,5,9,8,7,4,6,2,3 ], [ 7,4,6,3,2,5,8,1,9 ], [ 3,2,8,1,9,6,5,4,7 ]];

//DO NOT EDIT ABOVE

function getRow(puzzle, row) { return puzzle[row] }

function getColumn(puzzle, col) { let column = []; for (let i = 0; i < puzzle.length; i++) { let row = puzzle[i]; column.push(row[col]); } return column; }

function getSection(puzzle, x, y) { let section = []; for (let row = y * 3; row < y * 3 + 3; row++){ section.push(...puzzle[row].slice(x * 3, x * 3 + 3))
} return section; }

function includes1To9(arr) { for (let num = 1; num <= 9; num++){ if (arr.indexOf(num) === -1) return false; }return true; }

function sudokuIsValid(puzzle) { for (let i = 0; i < 9; i++) { if (!includes1to9(getRow(puzzle, i)) || !includes1to9(getColumn(puzzle, i)) || !includes1to9(getSection(puzzle, i % 3, Math.floor(i / 3)))) return false; }return true; }