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<HTML
><HEAD
><TITLE
>empty</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.57"><LINK
REL="HOME"
TITLE="PHP Manual"
HREF="manual.html"><LINK
REL="UP"
TITLE="Variable Functions"
HREF="ref.var.html"><LINK
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TITLE="doubleval"
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HREF="function.gettype.html"><META
NAME="HTTP_EQUIV"
CONTENT="text/html; charset=ISO-8859-1"></HEAD
><BODY
CLASS="refentry"
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
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ALIGN="left"
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><A
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>Prev</A
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></TD
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><A
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>Next</A
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><HR
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WIDTH="100%"></DIV
><H1
><A
NAME="function.empty"
>empty</A
></H1
><DIV
CLASS="refnamediv"
><A
NAME="AEN38586"
></A
><P
> (unknown)</P
>empty -- Determine whether a variable is set</DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN38589"
></A
><H2
>Description</H2
><DIV
CLASS="funcsynopsis"
><A
NAME="AEN38591"
></A
><P
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="function"
>empty</B
></CODE
> (mixed var)</CODE
></P
><P
></P
></DIV
><P
> Returns false if <TT
CLASS="parameter"
><I
>var</I
></TT
> is set and has a
non-empty or non-zero value; true otherwise.
<DIV
CLASS="informalexample"
><A
NAME="AEN38599"
></A
><P
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
> $var = 0;
if (empty($var)) { // evaluates true
echo '$var is either 0 or not set at all';
}
if (!isset($var)) { // evaluates false
echo '$var is not set at all';
}
</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
</P
><P
> Note that this is meaningless when used on anything which isn't a
variable; i.e. <B
CLASS="command"
>empty (addslashes ($name))</B
> has
no meaning since it would be checking whether something which
isn't a variable is a variable with a false value.
</P
><P
> See also <A
HREF="function.isset.html"
><B
CLASS="function"
>isset()</B
></A
> and
<A
HREF="function.unset.html"
><B
CLASS="function"
>unset()</B
></A
>.
</P
></DIV
><DIV
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><HR
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><TD
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><A
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><A
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