Before: 17
In function bar, $foo = 1
After: 17


$array['the'] = end


$array['the'] = end



Iterate using while and list:
$array[0] = "1"
$array[3] = ""
$array[5] = ""
$array[the] = "end"
$array[2] = "0"
$array[6] = "extra one"


print_r($array):
Array
(
    [0] => 1
    [3] => 
    [5] => 
    [the] => end
    [2] => 0
    [6] => extra one
)


var_dump($array):
array(6) {
  [0]=>
  int(1)
  [3]=>
  string(0) ""
  [5]=>
  bool(false)
  ["the"]=>
  string(3) "end"
  [2]=>
  int(0)
  [6]=>
  string(9) "extra one"
}