*** Testing array_push() : usage variations ***

-- Pass array as $var argument --
int(4)
array(4) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
  [3]=>
  array(2) {
    [0]=>
    string(3) "one"
    [1]=>
    string(3) "two"
  }
}

-- Pass sub-array as $stack argument --
int(3)
array(4) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
  [3]=>
  array(3) {
    [0]=>
    string(3) "one"
    [1]=>
    string(3) "two"
    [2]=>
    string(1) "a"
  }
}
Done