java - How to replace a string with dashes or question marks? -

so i'm in process of making hangman game user enters in word , word displayed disguised in question marks. every time user enters in word correctly, letter appears in place of question mark. have code necessary guessing , etc, need someones disguising word entered in user in question marks.

public static void main(string[] args) {     scanner bob = new scanner(system.in);     arraylist<string> alphabet = new arraylist<string>(arrays.aslist("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"));//i looked part mr. a, didn't know how directly set values in arraylist     int guesses = 6;//wrong guesses      system.out.println("hello! please enter in word game. 1 word allowed!");     string word = bob.next();     int lettersinword = word.length();//so know if you've solved word or not      while(guesses > 0 && lettersinword > 0){ //not or because you'll end getting negative 1         system.out.println("what guess? 1 letter @ time please or you'll mess game.");         string guess = bob.next();         guess.tolowercase(); //i populated arraylist lowercase letters has way         while(!alphabet.contains(guess)){ //since remove letters arraylist, default make sure guess doesn't happen twice             system.out.println("you guessed letter, or not letter");             guess = bob.next();//just lets user make guess         }         alphabet.remove(guess);//takes letter out of alphabet no redoes happen         if(word.contains(guess)){             system.out.println("yeauhhhhh, thats right! guessed " + guess);             lettersinword--;//makes word size smaller         } else {             system.out.println("nahhhhh, that's wrong! guessed " + guess + " , not in word");             guesses--;//takes guess away         }          system.out.println("you have " + guesses + " wrong guesses left"); //displays @ end of iteration     }     if(guesses == 0){//this comes when lose         system.out.println("you have lost, word "+ word);     } else {//this comes when you've guessed word, if not 1 other!!!         system.out.println("you have won! word  "+ word  + "good job dude. please see\n"                 + "mr. free piece of cake , 100 on final.");     } } 

you create separate string of question marks same length word.

string marks = ""; (int = 0; < word.length(); i++) {     marks += "?"; } 

when letter guessed correctly, replace question mark letter.