fix pr: 7763

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@35604 c90b9560-bf6c-de11-be94-00142212c4b1

functions/strings.xml

@@ -2425,6 +2425,28 @@ echo str_repeat ("-=", 10);
     </para>
     <para>
      If <parameter>needle</parameter> is not found, returns false.
+     <note>
+      <para>
+       It is easy to mistake the return values for "character found at
+       position 0" and "character not found".  Here's how to detect
+       the difference:
+       <informalexample>
+	<programlisting role="php">
+// in PHP 4.0b3 and newer:
+$pos = strrpos ($mystring, "b");
+if ($pos === false) { // note: three equal signs
+    // not found...
+}
+
+// in versions older than 4.0b3:
+$pos = strrpos ($mystring, "b");
+if (is_string ($pos) &amp;&amp; !$pos) {
+    // not found...
+}
+	</programlisting>
+       </informalexample>
+      </para>
+     </note>
     </para>
     <para>
      If <parameter>needle</parameter> is not a string, it is converted