Introduction and Code

1. Introduction and Code

2. Overview • In this presentation we will discuss: • What is Jeroo? • Where can you get it? • The story and syntax of Jeroo • How to create islands, write code and run programs. • Your first assignments.

3. What is Jeroo? • An environment for learning object oriented programming in Java, Basic or Python. (OOP). • you create objects and then do things with them. • Created in Java. • It’s free. www.jeroo.org

4. The story behind Jeroos • Jeroos • similar to the wallabies of Australia • have a pouch to hold flowers • Winsum Flower: Jeroo's source of food • Where they live: Santong Island in the South Pacific • can't swim – fur gets waterlogged-must dry • Humans arrive and set nets to catch Jeroos. • Jeroos try to avoid the nets

5. The Jeroo environment • The island is made of rows and columns. • Locations are written ( row, column) • The programmer chose to number both the rows and columns starting with zero at the northwest corner of the island. 2 0 1 3 4 columns 0 rows 1 NORTH 2 3 What location is this?

6. What a Jeroo can do • A Jeroo can execute 6 action methods • hop() hop once or hop(n) to hop n times • turn(relative_direction ) • pick()  pick a flower • plant()  plant a flower from the pouch • toss()  throw a flower 1 space ahead. • give(relativedirection)  give a flower to another Jeroo • They always follow directions in order, from top to bottom. • Put it all together to solve various problems. • Four relative directions: • LEFT • RIGHT • AHEAD • HERE When you turn or give, you must specify a relative direction turn(relative_direction ) give(relativedirection)

7. Creating a program in Jeroo • 3 steps: • Create the environment • Write the program • Run the program

8. Step 1. Create the Environment • To start: • Open an existing Island File • Or Create your own Island • Add or remove: • Flowers • Nets • Water • Be careful, this one is different: it resets the island • Land • You can save and re-use your islands.

9. Creating the Jeroo environment To create your environment in Jeroo: Left-click to draw Right-click to remove

10. Step 2. Write the program • You can create and control up to 4 Jeroos. • Your program must have a main method • { curly braces } surround statements to group them together • In Java every statement ends with a ; semicolon • Each Jeroo gets a name when it is created

11. The constructor statement • Jeroo alfred = new Jeroo(); • A new Jeroo is created and assigned the name alfred. • alfred will appear in the top left corner of the island, facing east. • All statements in the main program must specify which Jeroo is to act, and what it is to do. • alfred.toss(); • tells alfred to toss a flower into the space ahead.

12. Write the code to create a new Jeroo named neo Write the code to make neo hop Write the code to make neo turn right. Coding practice Answers: • Jeroo neo = new Jeroo(); • neo.hop( ); • neo.turn(RIGHT);

13. hopping • hop() alone means hop once in the direction the Jeroo is facing • hop(n) will tell the Jeroo to hop n times • Example: • alexandria.hop(3); • is the same as: • alexandria.hop(); • alexandria.hop(); • alexandria.hop(); • Write the code to make neo hop forward 5 times . • neo.hop(5);

14. Step 3: Run the program • Animation shows Jeroos moving around the island • Source code highlights while executing • You can run one step at a time • Run the whole program continuously • Pause at any time • Go back to the beginning,or stop

15. Step 3: Run the program • 3 different language modes • You want Java/C++/C#

16. Watch a program running • the code is highlighted • the Jeroo acts

17. Find the logic errors Go to Jeroo and demonstrate and fix alexandria

18. Lab 1 • Start Jeroo • Enter your name • 1. Create the environment • Clear the island layout. • Place a flower at location Row 3 Column 2 • 2. Write the program • Create a Jeroo with your name • Tell it to hop to the flower • Tell it to pick the flower • 3. Run the program • If it doesn’t work, fix it!

19. The program goes in the main method • Create a Jeroo with your name • Jeroo mrsOC = new Jeroo( ); • It will appear in location 0,0 facing EAST with no flowers in its pouch. • Tell it to hop onto the location with the flower • mrsOC.hop( ); • You must address your Jeroo by name. • repeat this statement each time you want your Jeroo to hop mrsOC.turn (relative direction); • You must turn either LEFT or RIGHT • Tell it to pick the flower • mrsOC.pick( ); • It will stop when it reaches the end of the program.

20. Icons used to create and edit islands • Set the speed of the Jeroos • Create a new island layout • Open an existing island • Save the island • Save as • Print • Plant flowers on the island • Set nets on the island • Add water to the island • Clear the island layout (remove all extra flowers, water and nets) • Get help with the Jeroo language • Quit Jeroo

21. First Assignment Create an attractive island based on your initials using water, land, flowers and nets. • Learn how to create islands. • Select water, flower or net • left-click to add • right-click to remove • Learn how to save islands. • Programs and islands are saved separately • Source_file save (.jsc) • Island_file save (.jev)

22. Top Grade • Write a program to get a Jeroo from one end of your original letter island to the other using AT LEAST 8 programming steps. • Add a comment to your code with your name in it and print the code. • (comments start with //)

23. The End