Lecture Notes: Teaching Karel to Turn Right

Introduction

• Problem Identified: Karel, the robot dog, cannot execute the command to turn right.
• Example Scenario: In the "Build a Tower" program, Karel needs to place a stack of three tennis balls and face east on top of the tower.
  • Users may attempt to use turnRight(); as a command, but it results in an error as Karel only understands the turnLeft command.

Solution: Using Functions

• Concept of Functions:
  • Functions allow us to teach Karel new commands.
  • A function defines a new behavior or command that Karel can understand and execute.

Creating a turnRight Function

• Function Definition:
  • Use the keyword function followed by the name of the function, turnRight.
  • Syntax: function turnRight() { // function body }
• Function Body:
  • Contains the instructions to execute the desired command.
  • For turnRight, the body consists of turning left three times: turnLeft(); turnLeft(); turnLeft();

Implementation Steps

1. Write the turnRight Function:
   • Define the function in the code with the correct syntax.
   • Place the commands to turn left three times inside the function.
2. Using turnRight in the Code:
   • After defining the function, it can be called using turnRight(); wherever needed in the code.

Conclusion

• Testing the Function:
  • After defining turnRight, reset and run the program.
  • Verify that Karel executes the turn right command correctly, solving the initial problem.