超越PHP - Exceed PHP: func_get_arg

Description

mixed func_get_arg ( int arg_num)

Returns the argument which is at the arg_num'th offset into a user-defined function's argument list. Function arguments are counted starting from zero. func_get_arg() will generate a warning if called from outside of a function definition. This function cannot be used directly as a function parameter. Instead, its result may be assigned to a variable, which can then be passed to the function.

If arg_num is greater than the number of arguments actually passed, a warning will be generated and func_get_arg() will return FALSE.


<?php

function foo() 

{

     $numargs = func_num_args();

     echo "Number of arguments: $numargs<br />\n";

     if ($numargs >= 2) {

     echo "Second argument is: " . func_get_arg(1) . "<br />\n";

     }

} 



foo (1, 2, 3);

?>

func_get_arg() may be used in conjunction with func_num_args() and func_get_args() to allow user-defined functions to accept variable-length argument lists.

add a note User Contributed Notes
func_get_arg

martin at classaxe dot com
08-Jun-2002 01:55

This function whilst elegant doesn't in itself avoid the problem of
generating warning messages where variables are not set, unless of course
you switched warnings off:
error_reporting(E_ERROR);

The answer
for those of who like to see necessary warnings?
Call it like
this:
@allSet($w, $x, $y, $z)

(Martin Francis)

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