function Func_get_args explanation ____ function

function foo ()
{
    $numargs = Func_num_args ();//number
    of parameters echo "number of parameters: $numargs <br/>\n";
    if ($numargs >= 2) {
        echo "the value of the second argument:". Func_get_arg (1). "<br/>\n";
    }
    $arg _list = Func_get_args ();
    for ($i = 0; $i < $numargs; $i + +) {
        echo {$i} parameter values: {$arg _list[$i]}<br/>\n ";
    }
}
 
Foo (1, ' d ', 3,4);

Output:
Number of parameters: 4
Value of the second parameter: D
No. 0 Parameter value: 1
1th parameter value: D
2nd parameter value: 3
3rd parameter value: 4