Documentation Bug #2965

"Why is ('Z'+1) < 'Z'?"


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@106290 c90b9560-bf6c-de11-be94-00142212c4b1

language/variables.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.55 $ -->
+<!-- $Revision: 1.56 $ -->
  <chapter id="language.variables">
   <title>Variables</title>
   
@@ -109,7 +109,35 @@ $bar = &test();    // Invalid.
      </programlisting>
     </informalexample>
    </para>
+   <para>
+    PHP follows Perl's convention when dealing with arithmetic operations
+    on character variables and not C's.  For example, in Perl 'Z'+1 turns
+    into 'AA', while in C 'Z'+1 turns into '[' { ord('Z') == 90, ord('[') == 91 ).
+    <example>
+     <title>Arithmetric Operations on Character Variables</title>
+     <programlisting role="php">
+<![CDATA[
+<?php
+$i = 'W';
+for($n=0; $n<6; $n++)
+  echo ++$i . "\n";
 
+/*
+  Produces the output similar to the following:
+
+X
+Y
+Z
+AA
+AB
+AC
+
+*/
+?>
+]]>
+     </programlisting>
+    </example>
+   </para>
   </sect1>
 
   <sect1 id="language.variables.predefined">