PHP Manual: func_get

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.

Note: Because this function depends on the current scope to determine parameter details, it cannot be used as a function parameter. If you must pass this value, assign the results to a variable, and pass the variable.

<?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.