Game Extras

1. Game Extras Pepper

2. Arrays Vs ArrayList (for our games) • Array • Fixed size: Cannot change size once it is created • Has length property, but no methods on the array as a whole • Can be used by Arrays class methods • ArrayList • Variable size: can add or remove items to change array length • An Object: Has helpful methods available such as add and remove • Can be used by Collections class methods (shuffle) • Cannot hold primitives (int, char, double) • Import java.util.ArrayList;

3. Review Array syntax • Card[] c : creates variable to hold an array of Cards • new Card[5] : constructs object - 5 empty array spots for Cards • c[0] = new Card() : constructs a card object and places it into c[0] • c.length : array c's size

4. ArrayList Syntax (for game) • ArrayList<Card> cAL: creates variable to hold an array list of Cards • new ArrayList<Card>() : constructs object - unlimited empty Array list of Cards • cAL.add(new Card()): constructs a card object and places it at the end of the Array List of cards • cAL.set(1,newCard()) : constructs a card object and insert it inside the existing Array, pushing every following item after it • cAL.size() : array list c's size • cAL.get(0) : gets the array list's first item • See http://max.cs.kzoo.edu/AP/Workshops/Java/ArraysArrayLists.html

5. Converting between the two • ArrayList to Array: • Ask the ArrayList to give you its elements as an array: • cAL.toArray(new Card[0] ) returns an array • Array to ArrayList: • Ask the static Arrays class to give you an array's elements as an ArrayList • Arrayd.asList(c) returns an arrayList of the array's generic object type

6. Some Helpful ArrayList Methods • Collections.shuffle(cAL) : This method takes in an array list and shuffles it directly. • cAL.remove(0): This asks the arrayList to remove its first item. The array will be a smaller size

7. Shuffling an array • Many methods available • One choice (though not perfect) • Loop through your array getting a random number within the size of your array • int index = rnd.nextInt(a.length); • Swap the cell of your counter with the cell of the random number • int hold = a[index] // save the card you will swap • a[index] = a[counter] // your loop counter value • a[counter] = hold // finish the swap

8. Player Class Use and Testing • Unit testing - Use tester to test methods before using in your game • See the value? • Code toString Method for easy printing • You can pass a player into any static method to reduce copied lines of code for each player

9. Tester • Right click class to add test case • Remove extends junit.framework.TestCase • Set up Players to use for your test in testSomething, or as Class variables: Player t1 = new Player("John"); t1.place= 5; Player t2 = new Player("Ann"); • Add test cases by calling those players: t.checkExpect(t1.movePlayer(3), 8); t.checkExpect(t2.movePlayer(3), 4);

10. Test using toString • System.out.println(player1) prints garbage with special characters • Create a toString method for your player to return a String describing the player nicely • public String toString(){return "name is " + this.name + " and his location is " + this.loc;} • Make a nice string to display all your variables • Then you can easily add many System.out.println(player1) statements to help you test.

11. Pass a player to a Turn method • Extract everything that happens for one player into one method: • Find the place one player's turn starts and the place it ends - cut that code • Replace it with a takeTurn() • Create a new takeTurn(Player p) method below main and paste the cut code into this method • Adjust the turn to use the player named p. • It will directly effect the player created in main.