<HTML ><HEAD ><TITLE >Initializers</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="PHP Manual" HREF="index.html"><LINK REL="UP" TITLE="Migrating from PHP 3 to PHP 4" HREF="migration4.html"><LINK REL="PREVIOUS" TITLE="Error reporting" HREF="migration4.error-reporting.html"><LINK REL="NEXT" TITLE='empty("0")' HREF="migration4.empty.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=ISO-8859-1"></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" >PHP Manual</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="migration4.error-reporting.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Appendix B. Migrating from PHP 3 to PHP 4</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="migration4.empty.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="migration4.initializers" ></A >Initializers</H1 ><P > Static variable and class member initializers only accept scalar values while in PHP 3 they accepted any valid expression. This is, once again, due to the split between parsing and execution as no code has yet been executed when the parser sees the initializer. </P ><P > For classes you should use constructors to initialize member variables instead. For static variables anything but a simple static value rarely makes sense anyway. </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="migration4.error-reporting.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="migration4.empty.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Error reporting</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="migration4.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><TT CLASS="literal" >empty("0")</TT ></TD ></TR ></TABLE ></DIV ></BODY ></HTML >