If your code works but fails the CodeHS grading checks, verify these three common issues:
Many exercises require Karel to end facing a specific direction (usually East). If your code finishes the task but Karel is facing North, the Autograder will mark it wrong.
Karel starts at (1,1) facing East. There are balls scattered in a line. Pick them all up. Solution:
Breaking a massive problem (like building a house or cleaning a grid) into tiny, manageable steps. codehs all answers karel top
If your code passes some test cases but fails others, check for these common pitfalls:
function start() move(); buildTower(); comeDown(); move(); move(); buildTower(); comeDown(); move(); turnLeft(); function buildTower() turnLeft(); putBall(); move(); putBall(); move(); putBall(); function comeDown() turnAround(); move(); move(); function turnAround() turnLeft(); turnLeft(); Use code with caution. 3. Advanced Karel Control Structures Control Structures Cheat Sheet Syntax Example Best Used For for (let i = 0; i < 4; i++) ...
buildTower() will turn Karel North, place a ball, move, place a ball, and move. If your code works but fails the CodeHS
function turnRight() turnLeft(); turnLeft(); turnLeft();
Use when you know exactly how many times to repeat something. Use while loops when repetition depends on a condition that might change — like moving until you hit a wall.
Students looking for "all answers" typically want a repository of working code for every single exercise. There are balls scattered in a line
Use an if statement when you want Karel to perform an action, but only if a certain condition is met. For example, the code below will check if Karel is facing a wall. If he is, he will turn left; if not, the code inside the if block is simply skipped.
def move_to_next_row(): turnLeft() move() turnLeft()
// Add a clever trick to get the top score for (var j = 0; j < 5; j++) move(); turnRight();
hosts active discussions for specific CodeHS exercises, including "1.4.6 Digging Karel," "CodeHS 4.3.2 Fetch Puzzle," and "CodeHS 3.4.4 Go Down the Slide Part Two".