: Each square must be perfectly positioned based on its width and height.
Cracking the Code: How to Fix CodeHS 9.1.6 Checkerboard V1 If you're stuck on CodeHS 9.1.6: Checkerboard, v1
The most efficient way to determine the color of a square is by checking the sum of its coordinates: 916 checkerboard v1 codehs fixed
Switch to the (row + col) % 2 == 0 check. This relies on absolute grid coordinates rather than stateful boolean switches. 2. Off-by-One Tracking Errors
: Do not define your print_board function inside another function or loop; it should be at the top level of your script. : Each square must be perfectly positioned based
The checkerboard problem isn’t just about drawing a pretty pattern. It teaches:
Ensure your loop variables start at 0 and terminate strictly before reaching the maximum count: for (int r = 0; r < max; r++) . 3. Execution Scope Mistakes It teaches: Ensure your loop variables start at
Inside a nested loop, use the mathematical property of a checkerboard: an element should be if the sum of its row and column indices is an even number . Example: At board[0][0] , (even), so it becomes Example: At board[0][1] , (odd), so it remains
The outer loop ( i ) handles the rows, while the inner loop ( j ) handles the individual columns within that row.
# Logic to move the turtle to the start of the next row # Note: The loop logic handles this via math, or you can update y manually. # The loop above uses math (j+1)*SIZE to handle x movement automatically.
The 9.1.6 Checkerboard v1 exercise is a classic milestone in the CodeHS computer science curriculum. It challenges students to transition from writing basic sequential code to implementing multi-layered loops and conditional logic.