Basic Code Tracing (Robot)

The APCSP pseudocode (and exam) have a few specialized instructions that let them ask "robot" questions. Basically their robot (it's a triangle) is an object (or sprite) and it can move and turn in a 2-dimensional grid world.

Here's an example of the robot in a world. In this example, the robot is in the bottom right corner and starts off facing left. Here's how robot worlds work

• It can move into any white block
• It cannot move into a black block or "outside" the grid
• When there are grey blocks in a robot example, it is the "final location" we want the robot to end up in.

Robot Methods (Procedures)

The robot can move with these methods:

• MOVE_FORWARD()
• ROTATE_LEFT()
• ROTATE_RIGHT()

The methods have no parameters. Moving always moves one block forward. Rotating turns the robot in place and always turns 90 degrees.

Robot Code Tracing with Grey "Target" Square (pick which code gets you to target) - Block Pseudocode

This shows you how to identify a robot code tracing question and gives you 3 steps to follow to answer these type of questions. If you can get used to identifying them, you can skip reading a lot of the words in the question (letting you do it faster). (12 minutes)

Robot Code Tracing with "Where does robot end up"? - Block Pseudocode with Variables

This shows you another type of robot question - where they ask you where the robot will be in the grid world after the code runs. This also combines using a variable. (9 minutes)

Robot Code Tracing with "Which World Won't Work" - Text Pseudocode

This is one of the more time consuming type of questions, so you may want to skip over it in timed test situations. It's (generally) hard to reduce the possible options with "test taking skills". You just have to trace each answer option. (12 minutes)