title: Is there an equivalent of "let" vs. "var" in PHP?
body: <p>I have recently started with learning Swift for iOS development. I have a background in scripting languages, especially PHP. Seeing that it is emphasized using <code>let</code> to define a constant in favor of <code>var</code> to have the compiler optimize the resulting code, I wondered: is there an equivalent for PHP? Or does it simply not apply as PHP is not statically compiled?</p>
  
  <p>I tried my luck at searching but found no satisfying information on that point.</p>