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>Passing by Reference</H1
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>&#13;   You can pass variable to function by reference, so that function could modify
   its arguments. The syntax is as follows:
    <DIV
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><PRE
CLASS="php"
>function foo (&#38;$var)
{
    $var++;
}

$a=5;
foo ($a);
// $a is 6 here</PRE
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>
  Note that there's no reference sign on function call - only on
  function definition. Function definition alone is enough to
  correctly pass the argument by reference. 
  </P
><P
>&#13;  Following things can be passed by reference:
   <P
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>&#13;      Variable, i.e. <TT
CLASS="literal"
>foo($a)</TT
>
     </P
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>&#13;      New statement, i.e. <TT
CLASS="literal"
>foo(new foobar())</TT
>
     </P
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>&#13;      Reference, returned from a function, i.e.:
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><PRE
CLASS="php"
>function &#38;bar()
{
    $a = 5;
    return $a;
}
foo(bar());</PRE
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>
    See also explanations about <A
HREF="language.references.return.html"
>returning by reference</A
>. 
     </P
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>
  </P
><P
>&#13;  Any other expression should not be passed by reference, as the
  result is undefined. For example, the following examples of passing
  by reference are invalid:
    <DIV
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><PRE
CLASS="php"
>function bar() // Note the missing &#38;
{
    $a = 5;
    return $a;
}
foo(bar());

foo($a = 5) // Expression, not variable
foo(5) // Constant, not variable</PRE
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>
		These requirements are for PHP 4.0.4 and later.
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