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>define</A
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>define -- Defines a named constant.</DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN17237"
></A
><H2
>Description</H2
><DIV
CLASS="funcsynopsis"
><P
></P
><CODE
CLASS="FUNCDEF"
>int define</CODE
>(string name, mixed value, int
[<SPAN
CLASS="optional"
>case_insensitive</SPAN
>]
);<P
></P
></DIV
><P
> Defines a named constant, which is similar to a variable except:
<P
></P
><UL
><LI
><P
> Constants do not have a dollar sign '$' before them;
</P
></LI
><LI
><P
> Constants may be accessed anywhere without regard to variable
scoping rules;
</P
></LI
><LI
><P
> Constants may not be redefined or undefined once they have
been set; and
</P
></LI
><LI
><P
> Constants may only evaluate to scalar values.
</P
></LI
></UL
>
</P
><P
> The name of the constant is given by <TT
CLASS="parameter"
><I
>name</I
></TT
>;
the value is given by <TT
CLASS="parameter"
><I
>value</I
></TT
>.
</P
><P
> The optional third parameter
<TT
CLASS="parameter"
><I
>case_insensitive</I
></TT
> is also available. If the
value <I
CLASS="emphasis"
>1</I
> is given, then the constant will be
defined case-insensitive. The default behaviour is
case-sensitive; i.e. CONSTANT and Constant represent different
values.
</P
><P
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><B
>Example 1. Defining Constants</B
></P
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><TR
><TD
><PRE
CLASS="programlisting"
> 1
2 <?php
3 define ("CONSTANT", "Hello world.");
4 echo CONSTANT; // outputs "Hello world."
5 ?>
6 </PRE
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>
</P
><P
> <B
CLASS="function"
>define()</B
> returns TRUE on success and FALSE if
an error occurs.
</P
><P
> See also <A
HREF="function.defined.html"
><B
CLASS="function"
>defined()</B
></A
> and the section on <A
HREF="language.constants.html"
>Constants</A
>.
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