1Note: Original slides provided by www.apComputerScience.com

and modified for this specific class

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• 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)

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• It’s pure Java • 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

• 7 Week timeframe which includes lectures, homework, labs, quizzes, and tests

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• Robot World– A flat plane of streets (east-west) and AVenues (north-south)

Corner (many robots may occupy)

Streets

Aven

ues

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• Bounded on west side by an 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

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• 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

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• 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.

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1. Factory - Builds the robots– Standard model– New model

• Extension of an existing base model2. Factory – Delivers the robots

“factory”(auf Deutsch)

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• 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

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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.

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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.