CS124, Fall 2021, Lab 5

CS 124, Fall 2021
Lab 5: Hangman

For this lab, you will implement the game of Hangman, which is described below. You will write the program file, Hangman.java, from scratch. The program does not use JavaFX. However, it does need input from the user. To use TextIO in your program, remember that you need to copy the textio directory into same directory as the program. You could just copy-and-paste it from your lab2 folder. Also, remember to put "import textio.TextIO;" at the start of the program.

Please read the Program Requirements and Hints, at the end of this lab, before starting work on the program! And please spend some time designing the program before you start to code.

In the version of the game for this lab, the computer will always use the same word, which is pretty pointless. In the next lab, we will see how to add a list of words for the computer to use.

Your work for this lab is due at the start of next week's lab, as usual. You can just turn in a copy of the file Hangman.java. As long as your file is actually named Hangman.java, there is no need to put the file in a directory named lab5 (but you can do that if you want).

Change of plan on September 24: You will not turn in the version of Hangman from this lab. You will improve the program in Lab 6, and only the improved version will be turned in for grading.

Hangman

Hangman is a two-person game in which one player picks a secret word, and the other player tries to guess the letters that occur in the word. In the computer version, the computer picks the word, and the user tries to guess it.

Each time the user enters a letter, they are told whether or not it occurs in the word. If it does not occur, that counts as a bad guess. If the user reaches the maximum allowed number of bad guesses, they lose the game. They win the game by guessing all of the letters in the word before reaching the limit on bad guesses.

Here is what the first few moves in a game of Hangman might look like, when it is played in a Terminal, with the letters entered by the user shown in red:

Let's play Hangman!

The word has 13 letters.

What is your first letter? t
   Yes, the word contains a T.

The word so far:   _ _ _ T _ _ _ _ _ T _ _ _ 

Your previous guesses: T
What is your next letter? e
   Sorry, the word does not contains a E.
   You have now made 1 bad guesses.
   You have 6 guesses left.

The word so far:   _ _ _ T _ _ _ _ _ T _ _ _ 

Your previous guesses: ET
What is your next letter? i
   Yes, the word contains a I.

The word so far:   _ _ _ T _ _ _ I _ T I _ _ 

Your previous guesses: EIT
What is your next letter? s
   Sorry, the word does not contains a S.
   You have now made 2 bad guesses.
   You have 5 guesses left.

The word so far:   _ _ _ T _ _ _ I _ T I _ _ 

Your previous guesses: EIST
What is your next letter? n
   Yes, the word contains a N.

The word so far:   _ _ N T _ _ _ I _ T I _ N 

Your previous guesses: EINST
What is your next letter? r
   Yes, the word contains a R.

The word so far:   _ _ N T R _ _ I _ T I _ N 
      .
      .
      .

Program Requirements and Hints

You must implement the game fully. The game ends when the word is complete or when the user reaches the limit on bad guesses (7 in my program).

You must output the "word so far" in the format shown after each guess. Use an underscore character followed by a space to represent letters in the word that have not yet been guessed. Use the letter followed by a space if the letter has been guessed. Other than that, you don't need to follow the exact format shown above, but you do need to make the output neat and keep the reader fully informed about what is going on.

This is a preliminary version of the program that always uses the same word to be guessed by the user. You should store that word in a variable. However, your program must still work if a different word is stored in the variable. For example, always refer to the length of the word as word.length(), and not as a numerical value such as 13.

Hints:

You do not need to store a string like _ _ N T _ _ _ I _ T I _ N in a variable! You can go through the word and output the characters one-by-one.
You will need to keep a string that contains all of the letters that have been guessed by the user. Every time the user enters a letter, add it to that string.
You can use TextIO.getlnChar() to read a single character into a variable of type char.
It will be easiest if all the letters that you are working with are in upper case. You should convert the word to upper case. But you shouldn't force the user to enter upper case letters. If you have a variable of type char, and you want to convert it to upper case, you can do that with letter = Character.toUpperCase(letter).
It is suggested to use a while(true) loop, and use a break statement to exit the loop when the user wins or when the user loses.
It is easy to tell when the user loses. Checking that the user has won is harder. You have to figure out a way to check whether all of the letters in the word have been guessed, that is, whether they are all in the list of guessed letters.

Some things that are not required but might be nice: If the user guesses a letter that they have already guessed, you could just ask them to enter a different letter (and not count it as a bad guess even if the letter is not in the word). And you could print out the list of letters-guessed-so-far in alphabetical order; there was an example in class that showed pretty much how to do that without actually keeping the list in alphabetical order.