title: What does a Ajax call response like 'for (;;); { json data }' mean?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/3146798/why-do-people-put-code-like-throw-1-dont-be-evil-and-for-in-front-of">Why do people put code like &ldquo;throw 1; &lt;dont be evil&gt;&rdquo; and &ldquo;for(;;);&rdquo; in front of json responses?</a>  </p>
  </blockquote>
  
  
  
  <p>I found this kind of syntax being used on Facebook for Ajax calls. I'm confused on the <code>for (;;);</code> part in the beginning of response. What is it used for?</p>
  
  <p>This is the call and response: </p>
  
  <pre><code>GET http://0.131.channel.facebook.com/x/1476579705/51033089/false/p_1524926084=0
  </code></pre>
  
  <p>Response:</p>
  
  <pre><code>for (;;);{"t":"continue"}
  </code></pre>