HangmanLogicClass.java

public class HangmanLogic {

    private String word;
    private String guessedLetters;
    private int numberOfFaults;

    public HangmanLogic(String word) {
        this.word = word.toUpperCase();
        this.guessedLetters = "";
        this.numberOfFaults = 0;
    }

    public int numberOfFaults() {
        return this.numberOfFaults;
    }

    public String guessedLetters() {
        return this.guessedLetters;
    }

    public int losingFaultAmount() {
        return 12;
    }

    public void guessLetter(String letter) {
        // program here the functionality for making a guess

        // if the letter has already been guessed, nothing happens

        // it the word does not contains the guessed letter, number of faults increase
        // the letter is added among the already guessed letters
        
        if(guessedLetters.contains(letter)){
            
        }else if(word.contains(letter)){
            guessedLetters += letter;
        }else{
            numberOfFaults++;
            guessedLetters += letter;
        }
    }

    public String hiddenWord() {
        // program here the functionality for building the hidden word

        // create the hidden word by interating through this.word letter by letter
        // if the letter in turn is within the guessed words, put it in to the hidden word
        // if the letter is not among guessed, replace it with _ in the hidden word 

        // return the hidden word at the end
        int length = word.length();
        int i = 0;
        String hidden = "";
        while (i < length){
            char c = word.charAt(i);
            String character = "" + c;
            if(guessedLetters.contains(character)){
                hidden += word.charAt(i);
            }else{
                hidden += "_";
            }
            i++;
        }
        return hidden;
    }
}