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<HTML
><HEAD
><TITLE
>Spotting References</TITLE
><META
NAME="GENERATOR"
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TITLE="References Explained"
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><DIV
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><TABLE
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><TH
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>PHP Manual</TH
></TR
><TR
><TD
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ALIGN="left"
VALIGN="bottom"
><A
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>Prev</A
></TD
><TD
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>Chapter 14. References Explained</TD
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><A
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><HR
ALIGN="LEFT"
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><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="language.references.spot"
>Spotting References</A
></H1
><P
> Many syntax constructs in PHP are implemented via referencing
mechanisms, so everything told above about reference binding also
apply to these constructs. Some constructs, like passing and
returning by-reference, are mentioned above. Other constructs that
use references are:
</P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="references.global"
><TT
CLASS="literal"
>global</TT
> References</A
></H2
><P
> When you declare variable as <B
CLASS="command"
>global $var</B
> you
are in fact creating reference to a global variable. That means,
this is the same as:
<DIV
CLASS="informalexample"
><A
NAME="AEN3970"
></A
><P
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
> $var =& $GLOBALS["var"];
</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
</P
><P
> That means, for example, that unsetting <TT
CLASS="varname"
>$var</TT
>
won't unset global variable.
</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="references.this"
><TT
CLASS="literal"
>$this</TT
></A
></H2
><P
> In an object method, <TT
CLASS="varname"
>$this</TT
> is always reference
to the caller object.
</P
></DIV
></DIV
><DIV
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