The Ds\Deque::unshift() function is an inbuilt function in PHP which is used to add the value in front of the deque. Syntax:
void Ds\Deque::unshift( $values )
Parameters: This function accepts single parameter $values which holds the values to add in the front of the deque. Return Value: This function does not return any values. Below programs illustrate the Ds\Deque::unshift() function in PHP: Program 1:
php
<?php // Declare a deque $deq = new \Ds\Deque([10, 20, 30, 40]);
// Use Ds\Deque::unshift() function $deq -> unshift(5);
$deq -> unshift(7);
$deq -> unshift(8);
print_r( $deq );
?> |
Output:
Ds\Deque Object ( [0] => 8 [1] => 7 [2] => 5 [3] => 10 [4] => 20 [5] => 30 [6] => 40 )
Program 2:
php
<?php // Declare a deque $deq = new \Ds\Deque();
// Use Ds\Deque::unshift() function $deq -> unshift("Welcome");
$deq -> unshift("to");
$deq -> unshift("GeeksforGeeks");
var_dump( $deq );
// Declare another deque $deq = new \Ds\Deque([ 'G' , 'E' , 'E' , 'K' , 'S' ]);
// Use Ds\Deque::unshift() function $deq -> unshift("1");
$deq -> unshift("2");
$deq -> unshift("3");
var_dump( $deq );
?> |
Output:
object(Ds\Deque)#1 (3) { [0]=> string(13) "GeeksforGeeks" [1]=> string(2) "to" [2]=> string(7) "Welcome" } object(Ds\Deque)#2 (8) { [0]=> string(1) "3" [1]=> string(1) "2" [2]=> string(1) "1" [3]=> string(1) "G" [4]=> string(1) "E" [5]=> string(1) "E" [6]=> string(1) "K" [7]=> string(1) "S" }
Reference: https://www.php.net/manual/en/ds-deque.unshift.php