<HTML
><HEAD
><TITLE
>Function true/false return values</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.44"><LINK
REL="HOME"
TITLE="PHP Manual"
HREF="manual.html"><LINK
REL="UP"
TITLE="Migrating from PHP/FI 2.0 to PHP 3.0"
HREF="migration.html"><LINK
REL="PREVIOUS"
TITLE="Short-circuited boolean evaluation"
HREF="migration-booleval.html"><LINK
REL="NEXT"
TITLE="Other incompatibilities"
HREF="migration-other.html"></HEAD
><BODY
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><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="migration-booleval.html"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Appendix A. Migrating from PHP/FI 2.0 to PHP 3.0</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="migration-other.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="migration-truefalse"
>Function true/false return values</A
></H1
><P
> Most internal functions have been rewritten so they return TRUE
when successful and FALSE when failing, as opposed to 0 and -1 in
PHP/FI 2.0, respectively. The new behaviour allows for more
logical code, like <TT
CLASS="literal"
>$fp = fopen("/your/file") or
fail("darn!");</TT
>. Because PHP/FI 2.0 had no clear rules
for what functions should return when they failed, most such
scripts will probably have to be checked manually after using the
2.0 to 3.0 convertor.</P
><P
> <TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><P
><B
>Example A-9. Migration from 2.0: return values, old code</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
> 1
2 $fp = fopen($file, "r");
3 if ($fp == -1);
4 echo("Could not open $file for reading<br>\n");
5 endif;
6 </PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>
<TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><P
><B
>Example A-10. Migration from 2.0: return values, new code</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
> 1
2 $fp = @fopen($file, "r") or print("Could not open $file for reading<br>\n");
3 </PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
></P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="migration-booleval.html"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="manual.html"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="migration-other.html"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Short-circuited boolean evaluation</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="migration.html"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Other incompatibilities</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
