Use if(ballsPresent()) to have Karel only pick up a ball if one actually exists on that space.

Use while(frontIsClear()) to make Karel move until he hits a wall. This works regardless of the world size.

Before diving into specific levels, remember the four basic commands Karel knows out of the box: – Moves Karel forward one space. turnLeft(); – Rotates Karel 90 degrees to the left. putBall(); – Drops one ball on the current tile. takeBall(); – Picks up one ball from the current tile. Solving Top Karel Challenges 1.1.4: Your First Karel Program