hangman utility class

Utils.java

public class Utils {

    private static StringBuilder builder = new StringBuilder();

    public static String updateString(String word, String targetWord, char guess) {

        reset();
        builder.append(word);
        
        for (int i = 0; i < word.length(); i++) {
            if (targetWord.charAt(i) == guess){
                builder.setCharAt(i, guess);
            }
        }
        return builder.toString();
    }

    public static String buildInitialWordState(String word) {
        reset();
        for (int i = 0; i < word.length(); i++){
            builder.append("-");
        }
        return builder.toString();
    }

    public static boolean letterIsPresent(String word, char c) {
        for (int i = 0; i < word.length(); i++) {
            if (word.charAt(i) == c){
                return true;
            }
        }
        return false;
    }

    private static void reset(){
        builder.setLength(0);
    }
}