Fix the Plan

If the robot walks into a wall, your first feeling might be that the robot is silly. It is not. It followed the list exactly. The list had a mistake. That mistake is called a bug.

Good debuggers read from step one. Did forward mean one square? Did turn left happen before the next forward? One wrong word early can send the robot the wrong way later.

Open the robot lab with the Wrong turn plan. Step through until the bump. Pause on the step that sent the robot facing the wall.

Change many steps at once and you will not know which fix worked. Change one step, run the plan again, and watch. That is how real programmers work too.

Sometimes the fix is adding a step you forgot, like turn left before forward. Sometimes it is removing an extra turn. Write the new plan on paper first if the lab feels fast.

Watch the step-flow animation. See a plan fail, one line change, then success on the second run.

Finding bugs is normal work, not a sign you failed. Games, apps and satellites all ship with bugs that testers find later.

Ask a friend to read your plan aloud while you act it out. Fresh eyes spot missing steps quickly.

Next you will learn loops so you do not repeat the same mistake four times in a row.