Reversing the order of a condition to avoid hard-to-find assignment problems

conditions.php

<?php

//This is what I normally do:
if($something == "string") { ... }

//The problem is, if I accidentally miss an = then it would be an assignment!
if($something = "string") { /* uh oh! */ }

//To prevent this, get in the habit of reversing the order:
if("string" == $something) { ... }

//That way, if you miss an = and it becomes an assignment, it will throw an error!
if ("string" = $something) { /* you can't assign a value to a constant! */ }

Uncle Bob doesn't like it when people code that way:

http://thecleancoder.blogspot.com/2010/09/john-macintyres-clean-code-experience-1.html