Comment by snorkel

Headline of this post is totally false and this is not even a bug in PHP, it's clearly a bug in the poster's code, so Rasmus response is right. If you actually try doing this in PHP you get this:

   print number_format("",0);

   Warning: number_format() expects parameter 1 to be 
   double, string given in Command line code on line 1

So the poster willfully ignored the warning. You can fix this simply by casting the first arg as a numeric type:

   print number_format((int)"",0);
   0

Please, if you're this bad at programming and you willfully ignore warnings, don't file bugs, and please do not take a programming job at some place that does important things like air traffic control, banking, or life support systems.