function drawRow() while (frontIsClear()) putBall(); safeMove(); safeMove(); // Handle the final fencepost space if necessary Use code with caution.
This solution uses a nested loop to iterate over each square on the checkerboard. The color of each square is determined by the sum of its row and column indices. If the sum is even, the square is white; otherwise, it is black.
// Alternate color based on position if((row + col) % 2 === 0) rect.setColor("black"); else rect.setColor("white");
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. 916 checkerboard v1 codehs fixed
This is achieved using . The outer loop handles the vertical movement (y-coordinates), and the inner loop handles the horizontal movement (x-coordinates). Common Mistakes (Why your code is broken)
Karel must finish the grid without crashing into walls. Common Bugs in Student Code
: We multiply the column index by the diameter to move to the next "slot." We add the radius because circles in CodeHS are positioned by their center , not their top-left corner. If the sum is even, the square is
set square_size = 50 set rows = 8 set cols = 8
function main() while(leftIsClear()) fillRow(); repositionToNextRow(); fillRow(); // Fills the very last row // Function to fill a single row with alternating checkers function fillRow() putBeeper(); while(frontIsClear()) move(); if(frontIsClear()) move(); putBeeper(); // Function to handle moving to the next row and switching direction function repositionToNextRow() if(facingEast()) turnLeft(); if(frontIsClear()) move(); turnLeft(); else turnRight(); if(frontIsClear()) move(); turnRight(); // Helper function to turn right function turnRight() turnLeft(); turnLeft(); turnLeft(); Use code with caution. Detailed Breakdown of the Fixed Code
For text-based checkerboards in Python:
:
# Constants SIZE = 50 # Size of one square ROWS = 8 COLS = 8