title: Is micro-optimization worth the time?
body: <p>I am a PHP developer and I have always thought that micro-optimizations are not worth the time. If you really need that extra performance, you would either write your software so that it's architecturally faster, or you write a C++ extension to handle slow tasks (or better yet, compile the code using HipHop). However, today a work mate told me that there is a big difference in </p>
  
  <pre><code>is_array($array)
  </code></pre>
  
  <p>and</p>
  
  <pre><code>$array === (array) $array
  </code></pre>
  
  <p>and I was like "eh, that's a pointless comparison really", but he wouldn't agree with me.. and he is the best developer in our company and is taking charge of a website that does about 50 million SQL queries per day -- for instance. So, I am wondering here: could he be wrong or is micro-optimization really worth the time and when?</p>