COM6471 – Foundations of object-oriented programming Assignment 2023 – a Wordle simulator
This is the assignment for COM6471 Foundations of Object Oriented Programming, and it is worth 40% of your final module mark. The deadline for submission is 15.00 on Friday 15 December.
The aim of this assignment is to test your ability to:
● Write an object oriented program in Java that makes use of several different classes.
● Write classes from a basic specification, which is vague in some details.
Ensure that you read the entire assignment specification carefully before you begin. This is a challenging assignment, and you will need to allow some time to design your solution before you begin writing any code.
Introduction
This assignment requires you to build a Java program to simulate the popular game Wordle (see https://www.nytimes.com/games/wordle/index.html for details). In this game a 5-letter English word is chosen from a list, and the player must guess the word in six attempts or less. Following each guess, the player is told which characters in the guess are present in the chosen word, and which of these characters are in the right location. The player uses this information to deduce the chosen word.
In this assignment, you will write a Java program to simulate Wordle that will run in one of two modes:
1. Computer selects a word at random from a list that is stored in a text file, and the user has six attempts to guess the chosen word.
2. User selects a word from a list that is stored in a text file, and the computer has six attempts to guess the chosen word.
I have provided two Java classes, and your submission must use these classes, as well as others that are specified below.
Unfair means
We take the use of unfair means very seriously1. This is an individual assignment. You must work on it alone and hand in your own code. You must not share code with other students, or submit work done by another student, or anyone else.
You must not post this assignment to any website to seek assistance, and you must not use code downloaded from anywhere except the two classes I have made available on Blackboard. All submissions will be run through specialised software that detects similarity among Java programs, as well as similarity to online resources, and action will be taken in cases where unfair means are suspected.
1 https://sites.google.com/sheffield.ac.uk/compgtstudenthandbook/home/your-study/referencing-unfair-means
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Task and requirements Overview
The aim of this assignment is to write a Java program to simulate Wordle. Your code must include at least four classes:
● WordleGame.java – This class is provided for you to download from Blackboard. You must use this code, and it should not be modified in any way.
● BaseGame.java – An outline for this class is provided for you to download from Blackboard. You will need to populate the class with instance fields and methods.
● UserGuesses.java and ComputerGuesses.java – These classes should extend BaseGame.java, and each should provide a run() method that provides a concrete implementation of the abstract run() method in BaseGame.java.
Your program should compile with javac WordleGame.java, with java version 17 and should run when the user types java WordleGame. When it runs, your program will generate the following dialogue:
A new game has been created
Please select either (1) User guesses or (2) Computer guesses :
User guesses game
A game where the user guesses should then proceed as follows:
Please select either (1) User guesses or (2) Computer guesses : 1 Constructing a new game with user guesses
The computer has selected a word, and you have 6 attempts to guess it. The computer will respond with:
+ to denote a correct character in the right location.
* to denote a correct character.
X to denote an incorrect character.
Attempt 1 of 6
Available letters : abcdefghijklmnopqrstuvwxyz Please enter a word, 5 characters long : idler Checking -idler- is valid
Word -idler- contains a-z only
Word -idler- is valid
Your guess : idler
Response   : XX+*X
Attempt 2 of 6
Available letters : abc_efgh_jklmnopq_stuvwxyz Please enter a word, 5 characters long : uncle
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Checking -uncle- is valid
Word -uncle- contains a-z only
Word -uncle- is valid
Your guess : uncle
Response   : *XX*+
Attempt 3 of 6
Available letters : ab efgh_jklm_opq_stuvwxyz
Please enter a word, 5 characters long :
And so on, until all 6 attempts have been used.
The first stage is for the computer to select a word, at random, from a list of 5-letter words that are read in from a text file. This text file must be stored in the same folder as the Java source code. You can use EasyReader to read the list.
I have provided two text files for you to use. Each file has an integer on the first line, which gives the total number of words in the file. The file called FiveLetterWords.txt contains a list of 26 words, and is intended for you to use as you develop your code. Since the number of words is small, you will be able to check that your code is working correctly.
The second file is called sgb-words.txt, and is a list of 5757 commonly used 5-letter words2. Once you believe that your code is working correctly, your code should read in the words from this file instead.
The final version your program that you submit should upload and store the words from sgb- words.txt, which must be located in the same folder as the Java code. Do not prefix the filename with a path such as C:\MyJava\Assignment.
Each time the user enters a word, your program should check that it is a 5-letter word, and that it contains only alphabetic characters and hasn’t been tried before. If the word is too long, the user should try again:
Please enter a word, 5 characters long : 24gerg
Checking -24gerg- is valid
Word -24gerg- is not the right length
Word is not valid – try again
Please enter a word, 5 characters long :
In a similar way, if the word contains any incorrect characters, the user should try again:
Please enter a word, 5 characters long : 12345
Checking -12345- is valid
Word -12345- contains incorrect characters, use a-z only Word is not valid - try again
Please enter a word, 5 characters long :
2 Available for download from https://www-cs-faculty.stanford.edu/~knuth/sgb.html
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Similarly, if the word has been tried in previous attempt, your program should be able to tell in which attempt the word has been used (3/6 attempt below means the word never has been used in the third attempt) and ask the user should try a new word:
Please enter a word, 5 characters long : never Checking -never- is valid
Word -never- used in the 3/6 attempt, try another word Word is not valid - try again
Please enter a word, 5 characters long :
Following each attempt, your program should compare the selected word and the guessed word, and then produce a response that is composed of the three characters ‘+’, ‘*’, and ‘X’ indicating that the corresponding letters are in the correct location, present in the word, and not present in the word respectively. Your program should also be able to tell the repetition of letter(s) in the word. For example, if the correct answer is ‘never’, a response of ‘****X’ should be obtained for the guess ‘every’. This indicates there are two ‘e’s in the correct word. If the correct answer is ‘value’, a response of ‘**XXX’ should be obtained for the guess ‘every’. This indicates only one ‘e’ in the correct word. A list of available letters should then be updated, replacing those letters that are not in the word with the underscore character ‘_’.
At the end of the game, the user should be presented with a message that either congratulates the user for solving the puzzle, or explains that the maximum number of attempts has been exceeded and gives the correct answer:
Attempt 6 of 6
Available letters : ab_d_fghijk_m_opqrstuvwxyz Please enter a word, 5 characters long : uncle Checking -uncle- is valid
Word -uncle- contains a-z only
Word -uncle- is valid
Your guess : uncle
Response : *XXXX
You have not managed to guess the word this time. The correct answer was : fruit
Computer guesses game
If the user selects a game where the computer guesses, then the game should proceed as follows.
Please select either (1) User guesses or (2) Computer guesses : 2
Constructing a new game with Computer guesses
Select a word by choosing a number between 0 and 25 : 6
Attempt 1 of 6
Guess is : kicks
XXXXX
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Attempt 2 of 6
Correct word : great, previous guess : kicks
Total number of possible words is : 8
Selecting a random word number : 5/8
Guess is : tough
*XX*X
Attempt 3 of 6
Correct word : great, previous guess : tough
Total number of possible words is : 3
Selecting a random word number : 3/3
Guess is : never
X*XX*
Attempt 4 of 6
Correct word : great, previous guess : never
Total number of possible words is : 1
Selecting a random word number : 1/1
Guess is : great
+++++
If the answer is guessed correctly within 6 attempts, the remaining attempts will be skipped. If the correct answer has not been reached, your program should continue until all 6 attempts have been used.
First, the user should choose a word by selecting a number between zero and the number of words in the word list. In this example the word is chosen from the 26 words in the text file FiveLetterWords.txt, but your final submission should use the file sgb-words.txt so the word will be chosen from the 5757 words in this file.
The computer should then guess a random word from the complete list for the first attempt only. For each subsequent attempt, the computer should construct a new list of words that do not contain characters identified by ‘X’ in the response to the previous guess. You should decide on a suitable way to store each new list of words. A word will then be selected randomly from this list in the subsequent guess.
General requirements and implementation notes
● Your submission must conform to the specification below:
o Your submission must use WordleGame.java, and you should add your own code to
the template BaseGame.java.
o Your submission must also include the required classes UserGuesses.java and
ComputerGuesses.java
o Your code must operate exactly as shown in the examples above.
● Where there is no exact specification for the way the code should operate, you are free to choose a suitable approach.
● You may ask questions about these requirements, but we cannot provide help with your assignment code, and will not check your code before submission.
● Your code must compile from the command line, and should not be assigned to a package.
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● You can use any of the classes provided in the Java 17 API (https://docs.oracle.com/en/java/javase/17/docs/api/index.html) .
● Although you are free to use more advanced Java features not covered in COM6471 (e.g. the java Collections classes), it is not necessary to use them.
● You must not use any other third party Java API or code library except for the sheffield package, and the classes provided.
● Your code must read in a word list from the file sgb-words.txt, which must be stored in the same folder as the Java source code.
You should write your code using a code editor. You should compile and run your code in the Command window prompt (Windows PC) or a terminal window (Mac or Linux), which is independent from the code editor. Using an integrated development environment such as Eclipse or IntelliJ is not recommended because these tools are beyond the scope of this module. Using these tools will result in code that may not meet the general requirements listed above.
Getting started
As a first step you should write skeleton code for the UserGuesses and ComputerGuesses classes, which contains a constructor and a run() method, and uses System.out.println() to display where the focus of control is.
The next step is to consider how each of the classes in the program relates to the other classes. This is best done on a sheet of paper. You should identify what each class needs to know, and what each class needs to do in order to deliver the requirements.
You should also investigate if there are common behaviours and information that can be abstracted, and should consider if any additional classes are needed. You may decide that some variables can be defined as constants. Based on your analysis, you will be able to identify the instance fields and methods for each class.
Code each class incrementally and use a test harness – either a separate test class with a main method, or a main method embedded in the class.
Each time you make changes to the class, compile and test it. If it fails to compile, or runs incorrectly, then go back over your most recent changes and isolate the problem.
Submission and deliverables
Before you upload your code, check that it compiles on the command line using java. It is a good idea to check that it compiles and runs on one of the University computers. Check that your code is not part of a package. Do not submit archives (e.g. zip files) or .class files.
Your code should then be submitted as a java files and uploaded to Blackboard using the upload tool before the deadline of 15.00 on Friday 15 December.
Assessment
Your code will be assessed for functionality and style. A mark of zero will be awarded for programs that
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do not compile; it is therefore important that you check that your code compiles on a University computer with Java 17 before you submit it, in case there are any issues with the configuration of your own computer. In particular, you should check that your code and comments do not contain any Chinese characters.
Marks will be allocated as follows.
Half of the marks (20/40) will be awarded for functionality and half (20/40) for design, testing, and style. There are many different ways to code the solution to this assignment. There is no single “correct” solution, and I fully expect a range of implementations to be submitted. However, some solutions are better than others because they are more concise, and more readable.
Functionality will be assessed as follows:
● Code compiles. If your code does not compile because it is incomplete or contains an error then you will be awarded a mark of zero.
● The game is played correctly by the user : Computer selects random word from list stored in sgb-words.txt, user supplies up to 6 guesses, computer correctly identifies each character and returns the result (5 marks).
● The game is played correctly by the computer : User selects random word from list stored in sgb-words.txt, computer generates an initial random guess, and then correctly generates a reduced list of words based on comparison between the random guess and the chosen word, computer then selects a word from this reduced list (10 marks).
● User input is validated correctly at each stage (5 marks). Design, testing and style will be assessed as follows:
● Design. Each class in the design has clear responsibilities and collaborations with other classes, has an appropriate set of methods and instance fields, suitable access modifiers are used to preserve encapsulation, and abstraction is used to enable concise coding (5 marks).
● Testing. Evidence of code used to test the behaviour of each class. This could be either a test harness for each class, or a separate test class (5 marks).
● Style. Code is written with good style (10 marks). Code written in good style will have the following characteristics:
o Each class will have a header comment, typically specifying the program name, the author, and the date.
o Other comments will only be present where necessary to enable readability.
o The code is indented consistently throughout using four spaces and not tabs, so that the code in each method is easily identified.
o Variables and methods have meaningful names (except for loop variables, which can be a single letter, e.g. for (int j = 0; j <= max; j++) ). Variables and methods should be in camelCase (e.g. gameType).
o There are sufficient lines of code to meet the requirements, and no extra, unreachable, or unnecessary code or comments.
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