<?php
function small_numbers()
{
  return array (0, 1, 2);
}
list ($zero, $one, $two) = small_numbers();
var_dump($zero);
var_dump($one);
var_dump($two);
?>

int(0)
int(1)
int(2)

<?php
function small_numbers()
{
  return array (0, 1);
}
list ($zero, $one, $two) = small_numbers();
var_dump($zero);
var_dump($one);
var_dump($two);
?>

Notice: Undefined offset: 2 in D:\xampp\htdocs\t\test.php on line 6
int(0)
int(1)
NULL

<?php
function small_numbers()
{
  return array (0, 1 ,2 ,3);
}
list ($zero, $one, $two) = small_numbers();
var_dump($zero);
var_dump($one);
var_dump($two);
?>

int(0)
int(1)
int(2)

<?php
function small_numbers()
{
  return array (0, 1 , array('2'));
}
list ($zero, $one, $two) = small_numbers();
var_dump($zero);
var_dump($one);
var_dump($two);
?>

int(0)
int(1)
array(1) {
[0]=>
string(1) "2"
}