title: Character ArrayList outOfBounds exception
body: <p>Error : java.lang.IndexOutOfBoundsException: Invalid index 70, size is 10;</p>
  
  <p>I have created a function to create random Integer ArrayList, and to do some operations with it, now i a m trying to adapt it to Chars,and i got strange error, as it seems to me,the default chars array size is bigger then Integer one, but i am not sure.What can i do with this code?
  Function fails here : <code>numbers.set(rightNumbers.get(k),answer.charAt(k));</code></p>
  
  <pre><code> @Override
      public void charactersRandomise(String answer) {
          final String alphabet = "ABSDEFGHMN";
          final int N = alphabet.length();
          ArrayList&lt;Character&gt; numbers = new ArrayList&lt;Character&gt;();
          ArrayList&lt;Character&gt; rightNumbers = new ArrayList&lt;Character&gt;();
          Random randomGenerator = new Random();
          int i=0;
          Log.d("size",String.valueOf(N));
          while (numbers.size() &lt; 10) {
  
              char random = alphabet.charAt(randomGenerator.nextInt(N));
              if (!numbers.contains(random)) {
                  numbers.add(random);
                  Log.d("numbers", numbers.get(i).toString());
                  i++;
              }
          }
          int j=0;
          while (rightNumbers.size() &lt; answer.length()) {
              char random = alphabet.charAt(randomGenerator.nextInt(N));
              if (!rightNumbers.contains(random)) {
                  rightNumbers.add(random);
                  Log.d("RightNumbers",rightNumbers.get(j).toString());
                  j++;
              }
          }
          for(int k =0;k&lt;rightNumbers.size();k++){
              numbers.set(rightNumbers.get(k),answer.charAt(k));
              Log.d(rightNumbers.get(k)+"", numbers.get(rightNumbers.get(k)).toString());
          }
          for (int h=0;h&lt;numbers.size()-1;h++) {
              Log.d("newNumber", String.valueOf(numbers.get(h)));
          }
          for(int m=0;m&lt;buttons.length;m++){
              buttons[m].setText(numbers.get(m) + "");
          }
      }
  </code></pre>