PHP | Ds\Deque isEmpty() Function

The Ds\Deque::isEmpty() function is an inbuilt function in PHP which is used to check the Deque is empty or not.

Syntax:

public Ds\Deque::isEmpty( void ) : bool

Parameters: This function does not accept any parameter.

Return Value: This function returns true if the Deque is empty, else return false.

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

Program 1:

<?php

// Declare a deque
$deck = new \Ds\Deque([1, 2, 3, 4, 5, 6]);

echo("Original Deque\n");

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

// Use isEmpty() function to check
// the deque is empty or not
var_dump($deck->isEmpty());

?>

Output:

Original Deque
Ds\Deque Object
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
)
bool(false)

Program 2:

<?php

// Declare a deque
$deck = new \Ds\Deque([1, 2, 3, 4, 5, 6]);

echo("Original Deque\n");

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

// Clearing the Deque
$deck->clear();

// Use isEmpty() function to check
// the deque is empty or not
var_dump($deck->isEmpty());

?>

Output:

Original Deque
Ds\Deque Object
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
)
bool(true)

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