Hangman game, with secret word provided by user

Question

I recently started learning programming and in particular Java. I wrote this small hangman game which takes the input for the secret word from the user.

It all works as intended; I would like to know ways to optimize or improve this code (taking into account that the input must be taken from the user and not from a file).

import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("Write the word");
        String word = sc.nextLine();
        List<String> wordSeg = new ArrayList<>(word.length());
        for (int x = 0; x < word.length(); x++) {
            wordSeg.add("*");
        }
        int i = 0;
        int chancesLeft;
        String usedCharacters = "";
        while (i < 6) {
            chancesLeft = 6 - i;
            System.out.println("Write a character or a word");
            String character  = sc.nextLine();
            char characterChar = character.charAt(0);
            if (character.equals(word)){
                System.out.println("You won!");
                break;
            }
            else if (word.contains(Character.toString(characterChar)) && character.length() < 2){
                for (int indx = 0; indx < word.length(); indx++){
                    if (word.charAt(indx) == characterChar) {
                        wordSeg.set(indx, character);
                    }
                }
                System.out.print(wordSeg);
                continue;
            } else {
                usedCharacters = character + " - " + usedCharacters;
            }
            i++;
            System.out.println("Chances left: " + chancesLeft);
            System.out.println("Characters not included: " + usedCharacters);
        }
    }
}
```

Answer 1

As your wordSeg doesn't change in length I'd use an array instead of ArrayList (String[] wordSeg = new String[word.length]). To fill the array you'd need to change for loop setting to wordSeg[x] = "*"; (or use Array.fill(wordSeg, "*");, though this would require an additional import). Because wordSeg is a list, using StringBuilder to create current output/guess is really easy:

StringBuilder builder;
...
builder = new StringBuilder();
for (String ch : wordSeg) {  
    builder.append(ch);  
}  
System.out.println(builder.toString());

Then you can add a check to see if guessed matches word (if(builder.toString().equals(word)){).

Next I'd make usedCharacters an ArrayList so it looks cleaner when you output the contents, as currently there is a dangling -. You need to update value in else with usedCharacters.add(character).

Before the loop I'd create a boolean flag win that I would set when the word is guessed, so that after the loop the output can change on win/lose. I'd also update wording of Characters not included to be something like Wrong Guesses because if the word is test and I guess then, there are correct characters, but the guess is wrong.

I'd get rid of characterChar, as the else if already checks if character.length() < 2

chancesLeft is outputting the wrong value, need to add - 1 in output

Technically the scanner should be closed as well (sc.close())

Whole program:

import java.util.Scanner;
import java.util.ArrayList;
import java.lang.StringBuilder;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
                StringBuilder builder = new StringBuilder();  
        System.out.println("Write the word");
        String word = sc.nextLine();
        String[] wordSeg = new String[word.length()];
        //Arrays.fill(wordSeg, "*"); // if you use this don't forget the import
        for (int x = 0; x < word.length(); x++) {
            wordSeg[x] = "*";
        }
        int i = 0;
        int chancesLeft;
        ArrayList<String> usedCharacters = new ArrayList<String>();
        boolean win = false;
        while (i < 6) {
            chancesLeft = 6 - i;
            System.out.println("Write a character or a word");
            String character  = sc.nextLine();
            if (character.equals(word)){
              win = true;
              break;
            }
            else if (word.contains(character) && character.length() < 2){                
                for (int indx = 0; indx < word.length(); indx++){
                    if (word.charAt(indx) == character.charAt(0)) {
                        wordSeg[indx] = character;
                    }
                } 
                builder = new StringBuilder();
                for (String ch : wordSeg) {  
                    builder.append(ch);  
                }  
                System.out.println(builder.toString());
                if(builder.toString().equals(word)){
                  win = true;
                  break;
                }
                continue;
            } else {
                usedCharacters.add(character);
            }
            i++;
            System.out.println("Chances left: " + (chancesLeft-1));
            System.out.println("Wrong Guesses: " + usedCharacters);
        }
        if (win) {
          System.out.println("You Won!");
        } else {
          System.out.println("You lose!");
          System.out.println("The word was " + word);
        }
        sc.close();
    }
}