GOALS: The purpose of this activity is to gain exposure with using objects of the Random class, while loops controlling flow based on user input, and some String methods. Be sure to add the names of all members of your group to the top of the Yahtzee.java file.

Getting Started: You should navigate to
grab a copy of the activity5 folder, and copy it to your H:\ drive. Start BlueJ, open the activity5 project and add the names of all members of your group to the top of the Yahtzee.java file. You will submit the Yahtzee.java file (one per group) via Blackboard.

1. In BlueJ, create a Yahtzee object and call its tester() method. This method uses a few (new) methods from the InputReader class that get input from the user. You can look at the interface version of the InputReader class, to see what methods it offers, and a brief description of them. You may then need to look at the source code of the InputReader class as well. Look at the source code (in Yahtzee.java) for the tester() method. Some of the input method calls provide a question mark at the end of their parameter String, others (the last one) do not. Pay careful attention to this, as you will want to complete the Yahtzee.java file in a way that prints question marks in the usual fashion (they are there when they should be, and there are not 2 of them for a single question).
2. Now call the start() method of your Yahtzee object, to get a feel for how it works and responds to various responses you might give it. Try answering the would you like to play again questions with things like "maybe" or "sure thing". Can you answer with anything other that "yes" or "no" and not get an error message? Be careful here, you might have to look at source code to determine this answer correctly.
   
   
   
   
   
   
   
   
3. We want a method that rolls 5 dice and stores the results in the field rolls (an array of 5 ints). This is similar to the code I wrote in class Wednesday. You can use a for loop to do this. Near the middle of the Yahtzee.java file is a header for the rollDice() method. Write the body of that method. Be sure to use rolls.length, instead of 5 in this method (just in case we alter rolls later, and need to roll a different number of dice. Your rollDice() method can simply call the rollIt() method to produce the values of the dice.
   
   
4. Now modify the body of the while loop in the start() method, so that it calls the rollDice() method (so 5 dice get rolled and saved in the array rolls), print out the values of these rolls (call the printOut() method), and then asks if the user would like to roll again.
5. In the game of Yahtzee, you roll 5 dice, and then you decide for each die, whether to keep it, or re-roll it. Eventually (after 2 chances at re-rolling), you compare your 5 dice to standard outcomes (like 5 of a kind, a straight, or 2 pair). For us to implement this sort of behavior, we need a method say reRoll() that will take an int parameter, and re-roll the die with that index. This method will not return any value, and it will simply replace rolls[i] with a new value (from calling the rollIt() method), whenever the input parameter i is between 0 (inclusive) and rolls.length (exclusive). Write the reRoll() method at the bottom of your Yahtzee.java file. Test it out by rolling all 5 dice and then calling your reRoll() method with various input values (some from 0 to 4, others outside this range).
   
   
6. In order to utilize this reRoll() method, we will need to ask the user 5 questions (do they want to re-roll die 1, die 2, die 3, die 4, and die 5) and respond accordingly (by doing nothing if they do NOT want to re-roll that die, and re-rolling that die when they say yes). Modify your start() method so that it rolls all 5 dice (as before) and then asks these 5 questions, and re-rolls each die that the user would like to re-roll. Ideally, you could do this with a loop, but if you have to (for a few points less), you can simply write code that handles die1, then die 2, and so on. Once you've asked them these questions and re-rolled the appropriate dice, be sure to printout the results and ask if they would like to play again. One more note, in the gane of Yahtzee, you re-roll all of your dice at one time (those that you chose to re-roll anyway), so while you should probably re-roll each die immediately as you ask the user these questions, you should NOT print out the new values, until after they've decided whether or not to re-roll each of the dice.
   
7. In the game of Yahtzee, you roll all 5 dice, pick any subset (all 5 is allowed) of the 5 dice to re-roll, and then pick any subset (again all 5 can be re-rolled, and die that were left alone the first time can be re-rolled on this second pass) to re-roll a second time. Your goal is to get "poker-hands" (full houses, four of a kind etc.) with the 5 dice after all three "rolls" have been completed. Modify your start method so that it incorporates this second "re-rolling", therefore mimicing the game of Yahtzee itself.
8. Turn in your Yahtzee.java file on Blackboard (under assignments).