Source Code Fundamentals: Keywords

Keywords are reserved; they should not and usually cannot be used as names. Other words that shouldn't be used for names are the built-in types.

Keywords

abstract   as   async   attribute   await   break   case   catch   category   children   class   classname
clone   const   continue   default   do   echo   else   enum   eval   exit   extends   final   
finally   for   foreach   function   if   implements   include   include_once   inout   interface   invariant
isset   list   namespace   new   newtype   noreturn   parent   print   private   protected   public
require   required   require_once   return   self   shape   super   static   switch   throw   trait   try   tuple
type   unset   use   using   where   while   yield

Deprecated Keywords

In addition, the following keywords are reserved for historical / future usage:

and   declare   die   elseif   empty   enddeclare   endfor   endforeach   endif   endswitch
endwhile   global   goto   instanceof   insteadof   or   record   var   xor