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)
