Sophie: php-manual-en-4.3.0-2mdk noarch

php-manual-en-4.3.0-2mdk.noarch.rpm

<HTML
><HEAD
><TITLE
>NULL</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="Types"
HREF="language.types.html"><LINK
REL="PREVIOUS"
TITLE="Resource"
HREF="language.types.resource.html"><LINK
REL="NEXT"
TITLE="Pseudo-types used in this documentation"
HREF="language.pseudo-types.html"><META
HTTP-EQUIV="Content-type"
CONTENT="text/html; charset=ISO-8859-1"></HEAD
><BODY
CLASS="sect1"
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="language.types.resource.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 7. Types</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="language.pseudo-types.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="language.types.null"
></A
>NULL</H1
><P
>&#13;    The special <TT
CLASS="constant"
><B
>NULL</B
></TT
> value represents 
    that a variable has no value. <TT
CLASS="constant"
><B
>NULL</B
></TT
> is the only possible value of type
    NULL.
   </P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>
      The null type was introduced in PHP 4
     </P
></BLOCKQUOTE
></DIV
><P
>&#13;     A variable is considered to be <TT
CLASS="constant"
><B
>NULL</B
></TT
> if
     <P
></P
><UL
><LI
><P
>&#13;        it has been assigned the constant <TT
CLASS="constant"
><B
>NULL</B
></TT
>.
       </P
></LI
><LI
><P
>&#13;        it has not been set to any value yet.
       </P
></LI
><LI
><P
>&#13;        it has been <A
HREF="function.unset.html"
><B
CLASS="function"
>unset()</B
></A
>.
       </P
></LI
></UL
>
    </P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="language.types.null.syntax"
></A
>Syntax</H2
><P
>&#13;     There is only one value of type <TT
CLASS="constant"
><B
>NULL</B
></TT
>, and that is 
     the case-insensitive keyword <TT
CLASS="constant"
><B
>NULL</B
></TT
>.
     <DIV
CLASS="informalexample"
><A
NAME="AEN3847"
></A
><P
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
CELLPADDING="5"
><TR
><TD
><PRE
CLASS="php"
>&#60;?php
$var = NULL;       

?&#62;</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
    </P
><P
>&#13;     See also <A
HREF="function.is-null.html"
><B
CLASS="function"
>is_null()</B
></A
> and <A
HREF="function.unset.html"
><B
CLASS="function"
>unset()</B
></A
>.
    </P
></DIV
></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="language.types.resource.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="language.pseudo-types.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Resource</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="language.types.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Pseudo-types used in this documentation</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>