php func_get_arg

mixed func_get_arg ( int $arg_num )

该函数用于返回所在函数中指定索引的参数，索引从0开始

<?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);
?> 

array func_get_args ( void )

则将所有参数以数组形式返回

<?php
function foo() {
    include './fga.inc';
}

foo('First arg', 'Second arg');
?>

fga.inc
<?php

$args = func_get_args();
var_export($args);


//print : array (
//                   0 => 'First arg',
//                   1 => 'Second arg',
//                 )

?> 

int func_num_args ( void )

返回函数参数的总数

<?php
function foo()
{
    $numargs = func_num_args();
    echo "Number of arguments: $numargs\n";
}

foo(1, 2, 3);   

//print : Number of arguments: 3
?>