PHP | Ds\Deque reverse() Function

The Ds\Deque::reverse() function is an inbuilt function in PHP which is used to reverse the elements in the Deque in-place.

Syntax:

public Ds\Deque::reverse( void ) : void

Parameters: This function does not accept any parameter.

Return Value: This function does not return any value.

Below programs illustrate the Ds\Deque::reverse() function in PHP:

Program 1:

<?php

// Declare a deque
$deck = new \Ds\Deque([10, 20, 30, 40, 50, 60]);

echo("Elements of Deque\n");

// Display the Deque elements
var_dump($deck);

// Reversing the deque
$deck->reverse();

echo("\nElements of the reversed deque\n");

// Display the Deque elements
var_dump($deck);

?>

Output:

Elements of Deque
object(Ds\Deque)#1 (6) {
  [0]=>
  int(10)
  [1]=>
  int(20)
  [2]=>
  int(30)
  [3]=>
  int(40)
  [4]=>
  int(50)
  [5]=>
  int(60)
}

Elements of the reversed deque
object(Ds\Deque)#1 (6) {
  [0]=>
  int(60)
  [1]=>
  int(50)
  [2]=>
  int(40)
  [3]=>
  int(30)
  [4]=>
  int(20)
  [5]=>
  int(10)
}

Program 2:

<?php

// Declare a deque
$deck = new \Ds\Deque(["geeks", "GFG", "ABC"]);

echo("Elements of Deque\n");

// Display the Deque elements
print_r($deck);

// Reversing the deque
$deck->reverse();

echo("\nElements of the reversed deque\n");

// Display the Deque elements
print_r($deck);

?>

Output:

Elements of Deque
Ds\Deque Object
(
    [0] => geeks
    [1] => GFG
    [2] => ABC
)

Elements of the reversed deque
Ds\Deque Object
(
    [0] => ABC
    [1] => GFG
    [2] => geeks
)

Reference: http://php.net/manual/en/ds-deque.reverse.php