title: Identifying Unused Letters from an array
body: <p>I'm writing a hangman program in Java, but the problem I have is, in the game i want to show the remaining letter from the letters guessed, for that I have created a String alpha, which contains the alphabet, and i put that to an ArrayList so i can choose the letters that's been guesses by the player. but i'm stuck in this bit the out put i want to get is as below : and i've attached the code i wrote for the function as well.</p>
  
  <p>You have 6 guesses left.
  Available letters: abcdefghijklmnopqrstuvwxyz
  Please guess a letter: a</p>
  
  <h2>Good guess: a_ _</h2>
  
  <p>You have 6 guesses left.
  Available letters: bcdefghijklmnopqrstuvwxyz</p>
  
  <h2>code :</h2>
  
  <pre><code>public String getRemainingLetters(String[] lettersGuessed) {
  
      String alpha = "abcdefghijklmnopqrstuvwxyz";        
      String [] alpha2 = alpha.split("");          
      ArrayList&lt;String&gt; list = new ArrayList&lt;&gt;(Arrays.asList(alpha2));
  
      return null;
      // TODO: Fill in your code here
  }
  </code></pre>