Karel J Robot

1. Karel J Robot

2. Karel J Robot • Karel provides an OOP approach to learning computer science • It provides visual feedback to students – you get to see your mistakes and triumphs. • It will cover some of the major CS concepts in a short period of time: • Inheritance, Polymorphism, Abstraction, Encapsulation, OOP-Design, Recursion, Iteration, Selection, … • Filters out many(relevant) details so one can focus on the major concepts: • Not in danger of losing sight of the Forest (computer science) through the details of the Trees (java details)

3. Karel J Robot • It’s pureJava • It introduces many major topics in a short period of time – not too much detail • then, as the year goes on, we will spiral back through those topics introducing more and more detail as required • 1st term timeframe which includes lectures, homework, labs, quizzes, and assessments

4. Karel's World • Robot World • A flat plane of streets (east-west) and AVenues (north-south) Streets Corner (many robots may occupy) Avenues

5. Karel's World • Bounded on west side by an infinitely long vertical wall and on south side by infinitely long horizontal wall • Streets and avenues have numbers • Corner is identified by street and avenue. Origin is street 1, avenue 1. • Position of robots and other things can be referred to by an absolute or relative location

6. Karel's World • Contains Beepers and Walls • Beepers • Beep very softly. Robots cannot sense a beeper until they are on the same corner. • May be picked up, carried, and placed again • Several beepers can be placed on a corner and they don’t interfere with Robot movement • Walls • Placed half way between street corners • Impenetrable, blocks robots • Used to create rooms, mazes, hurdles

7. Wall Segments

8. Robot Capabilities • Moves • Only moves forward in direction top of its head is facing • Turns • Turns 90 degrees to the left • Senses surroundings • Hears beepers (on same corner) • Determines direction it is facing • Picks up, carries, and puts down beepers • Turns itself off I am facing West and have no beepers I am turned OFF. I can’t do anything else.

9. “factory”(auf Deutsch) Karel-Werke • Factory - Builds the robots • Standard model • New model • Extension of an existing base model • Factory – Delivers the robots

10. Robot Tasks and Situations • Examples: • Move to a corner (3rd St. & 5th Ave.) • Run a hurdle race • Escape from a maze • Find a beeper and deliver it to the origin • Draw a pattern with beepers

11. Robot Tasks and Situations Fig A: A room has one door. A robot is at the origin and facing North. Robot must enter the room. Fig B: A diagonal line of beepers. Robot is facing East and must pick up all beepers. Fig C: A “+” wall arrangement with beepers. From a starting position, Robot must pick up all beepers. Fig D: Robot must escape the maze.

12. Robot Tasks and Situations Fig E: Beepers are scattered in a box. Robot is facing South in the Northwest corner and must pick up all beepers in the box.. Fig F: Box with a beeper. Robot is facing North in the Northeast corner. Robot must find the beeper.

13. Karel Program

14. Using Eclipse Java Environment • Before you begin to write programs for Karel or Java, you will need to obtain a copy of Eclipse from http://www.eclipse.org/downloads/ website. • The process for downloading Eclipse depends on what system you are using. • The process may take a while, so be patient!

15. The Eclipse Interface

16. Coding Karel • import stanford.karel.*; • public class OurFirstKarelClass extends Karel { • public void run() { • turnLeft(); • move(); • pickBeeper(); • } • }

17. Defining new methods • Yes you can define new methods for Karel • private void turnRight() { • turnLeft(); • turnLeft(); • turnLeft(); • }