title: Discarding array item once used
body: <p>How can I make sure that a random number is only generated once?</p>
  
  <p>For example:</p>
  
  <pre><code>for(int i = 0; i&lt;len; i++)
      {
          while (rands.contains(rand = r.nextInt(len-2)+1));
          rands.add(rand);
          System.out.print ("Rand ___ " + rand + "___");
      }
  </code></pre>
  
  <p>How can I make sure that if the number 2 is generated from rand, it wont be generated again?</p>
  
  <p>I apologise if i am not making myself clear enough. Please comment if you require any more information.</p>
  
  <p>Thanks.</p>