How to take STDIN in Swift playground
<p>I know that to program in STDIN and STDOUT, we need to make an command line project in Xcode. 
But how do I take a standard input in playground. </p>

<p>Whenever I try to run such code in playground</p>

<pre><code>var input = readLine()!
</code></pre>

<p>I always get this error</p>

<blockquote>
  <p>Execution was interrupted, reason: EXC_BAD_INSTRUCTION
  (Code=EXC_l386_INVOP, subcode=0x0)</p>
</blockquote>

<p>Is it possible to take STDIN in playground or not?</p>

<p><strong>UPDATE</strong></p>

<p>I know this error is because of <strong>nil</strong> <code>input</code> variable but want to know how to overcome this nil value.</p>