<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Backward Incompatible Changes</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="Manual do PHP" HREF="index.html"><LINK REL="UP" TITLE="Migrating from PHP 4 to PHP 5" HREF="migration5.html"><LINK REL="PREVIOUS" TITLE="Migrating from PHP 4 to PHP 5" HREF="migration5.html"><LINK REL="NEXT" TITLE="CLI and CGI" HREF="migration5.cli-cgi.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="section" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Manual do PHP</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="migration5.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Apêndice C. Migrating from PHP 4 to PHP 5</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="migration5.cli-cgi.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="migration5.incompatible" >Backward Incompatible Changes</A ></H1 ><P > Although most existing PHP 4 code should work without changes, you should pay attention to the following backward incompatible changes: </P ><P ></P ><UL ><LI ><P > There are some <A HREF="reserved.html#reserved.keywords" >new reserved keywords</A >. </P ></LI ><LI ><P > <A HREF="function.strrpos.html" ><B CLASS="function" >strrpos()</B ></A > and <A HREF="function.strripos.html" ><B CLASS="function" >strripos()</B ></A > now use the entire string as a needle. </P ></LI ><LI ><P > Illegal use of string offsets causes <TT CLASS="constant" ><B >E_ERROR</B ></TT > instead of <TT CLASS="constant" ><B >E_WARNING</B ></TT >. An example illegal use is: <TT CLASS="literal" >$str = 'abc'; unset($str[0]);</TT >. </P ></LI ><LI ><P > <A HREF="function.array-merge.html" ><B CLASS="function" >array_merge()</B ></A > was changed to accept only arrays. If a non-array variable is passed, a <TT CLASS="constant" ><B >E_WARNING</B ></TT > will be thrown for every such parameter. Be careful because your code may start emitting <TT CLASS="constant" ><B >E_WARNING</B ></TT > out of the blue. </P ></LI ><LI ><P > PATH_TRANSLATED server variable is no longer set implicitly under Apache2 SAPI in contrast to the situation in PHP 4, where it is set to the same value as the SCRIPT_FILENAME server variable when it is not populated by Apache. This change was made to comply with the <A HREF="http://hoohoo.ncsa.uiuc.edu/cgi/" TARGET="_top" >CGI specification</A >. Please refer to <A HREF="http://bugs.php.net/23610" TARGET="_top" >bug #23610</A > for further information, and see also the <A HREF="reserved.variables.html#reserved.variables.server" > $_SERVER['PATH_TRANSLATED']</A > description in the manual. This issue also affects PHP versions >= 4.3.2. </P ></LI ><LI ><P > The <TT CLASS="constant" ><B >T_ML_COMMENT</B ></TT > constant is no longer defined by the <A HREF="ref.tokenizer.html" >Tokenizer</A > extension. If error_reporting is set to <TT CLASS="constant" ><B >E_ALL</B ></TT >, PHP will generate a notice. Although the <TT CLASS="constant" ><B >T_ML_COMMENT</B ></TT > was never used at all, it was defined in PHP 4. In both PHP 4 and PHP 5 // and /* */ are resolved as the <TT CLASS="constant" ><B >T_COMMENT</B ></TT > constant. However the PHPDoc style comments /** */, which starting PHP 5 are parsed by PHP, are recognized as <TT CLASS="constant" ><B >T_DOC_COMMENT</B ></TT >. </P ></LI ><LI ><P > $_SERVER should be populated with argc and argv if <A HREF="ini.core.html#ini.variables-order" >variables_order</A > includes "S". If you have specifically configured your system to not create $_SERVER, then of course it shouldn't be there. The change was to always make argc and argv available in the CLI version regardless of the <A HREF="ini.core.html#ini.variables-order" >variables_order</A > setting. As in, the CLI version will now always populate the global $argc and $argv variables. </P ></LI ><LI ><P > An object with no properties is no longer considered "empty". </P ></LI ><LI ><P > In some cases classes must be declared before use. It only happens if some of the new features of PHP 5 (such as <A HREF="language.oop5.interfaces.html" >interfaces</A >) are used. Otherwise the behaviour is the old. </P ></LI ><LI ><P > <A HREF="function.get-class.html" ><B CLASS="function" >get_class()</B ></A >, <A HREF="function.get-parent-class.html" ><B CLASS="function" >get_parent_class()</B ></A > and <A HREF="function.get-class-methods.html" ><B CLASS="function" >get_class_methods()</B ></A > now return the name of the classes/methods as they were declared (case-sensitive) which may lead to problems in older scripts that rely on the previous behaviour (the class/method name was always returned lowercased). A possible solution is to search for those functions in all your scripts and use <A HREF="function.strtolower.html" ><B CLASS="function" >strtolower()</B ></A >. </P ><P > This case sensitivity change also applies to the <A HREF="language.constants.predefined.html" >magical predefined constants</A > <TT CLASS="constant" ><B >__CLASS__</B ></TT >, <TT CLASS="constant" ><B >__METHOD__</B ></TT >, and <TT CLASS="constant" ><B >__FUNCTION__</B ></TT >. The values are returned exactly as they're declared (case-sensitive). </P ></LI ><LI ><P > <A HREF="function.ip2long.html" ><B CLASS="function" >ip2long()</B ></A > now returns <TT CLASS="constant" ><B >FALSE</B ></TT > when an invalid IP address is passed as argument to the function, and no longer <TT CLASS="literal" >-1</TT >. </P ></LI ><LI ><P > If there are functions defined in the included file, they can be used in the main file independent if they are before <A HREF="function.return.html" ><B CLASS="function" >return()</B ></A > or after. If the file is included twice, PHP 5 issues fatal error because functions were already declared, while PHP 4 doesn't complain about it. It is recommended to use <A HREF="function.include-once.html" ><B CLASS="function" >include_once()</B ></A > instead of checking if the file was already included and conditionally return inside the included file. </P ></LI ><LI ><P > <A HREF="function.include-once.html" ><B CLASS="function" >include_once()</B ></A > and <A HREF="function.require-once.html" ><B CLASS="function" >require_once()</B ></A > first normalize the path of included file on Windows so that including A.php and a.php include the file just once. </P ></LI ></UL ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN275835" ></A ><P ><B >Exemplo C-1. <A HREF="function.strrpos.html" ><B CLASS="function" >strrpos()</B ></A > and <A HREF="function.strripos.html" ><B CLASS="function" >strripos()</B ></A > now use the entire string as a needle</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />var_dump</font><font color="#007700">(</font><font color="#0000BB">strrpos</font><font color="#007700">(</font><font color="#DD0000">'ABCDEF'</font><font color="#007700">,</font><font color="#DD0000">'DEF'</font><font color="#007700">)); </font><font color="#FF8000">//int(3)<br /><br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">strrpos</font><font color="#007700">(</font><font color="#DD0000">'ABCDEF'</font><font color="#007700">,</font><font color="#DD0000">'DAF'</font><font color="#007700">)); </font><font color="#FF8000">//bool(false)<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN275841" ></A ><P ><B >Exemplo C-2. An object with no properties is no longer considered "empty"</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">class </font><font color="#0000BB">test </font><font color="#007700">{ }<br /></font><font color="#0000BB">$t </font><font color="#007700">= new </font><font color="#0000BB">test</font><font color="#007700">();<br /><br /></font><font color="#0000BB">var_dump</font><font color="#007700">(empty(</font><font color="#0000BB">$t</font><font color="#007700">)); </font><font color="#FF8000">// echo bool(false)<br /><br /></font><font color="#007700">if (</font><font color="#0000BB">$t</font><font color="#007700">) {<br /> </font><font color="#FF8000">// Will be executed<br /></font><font color="#007700">}<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN275845" ></A ><P ><B >Exemplo C-3. In some cases classes must be declared before used</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /><br /></font><font color="#FF8000">//works with no errors:<br /></font><font color="#0000BB">$a </font><font color="#007700">= new </font><font color="#0000BB">a</font><font color="#007700">();<br />class </font><font color="#0000BB">a </font><font color="#007700">{<br />}<br /><br /><br /></font><font color="#FF8000">//throws an error:<br /></font><font color="#0000BB">$a </font><font color="#007700">= new </font><font color="#0000BB">b</font><font color="#007700">();<br /><br /></font><font color="#0000BB">interface c</font><font color="#007700">{<br />}<br />class </font><font color="#0000BB">b implements c </font><font color="#007700">{<br />} <br /><br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="migration5.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Principal</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="migration5.cli-cgi.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Migrating from PHP 4 to PHP 5</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="migration5.html" ACCESSKEY="U" >Acima</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >CLI and CGI</TD ></TR ></TABLE ></DIV ></BODY ></HTML >