PHP | Ds\Vector unshift() Function

The Ds\Vector::unshift() function is an inbuilt function in PHP which is used to adds elements to the front of vector. This function moves all the elements in the vector towards forward and adds the new element to the front.

Syntax:

void public Ds\Vector::unshift( $values )

Parameters: This function accepts single parameter $values which holds the values to be added to the vector.

Return Value: This function does not return any value.

Below programs illustrate the Ds\Vector::unshift() function in PHP:

Program 1:

<?php

// Create new Vector
$vect = new \Ds\Vector([3, 6, 1, 2, 9, 7]);

echo("Original vector:\n");

// Display the vector elements
print_r($vect);

echo("\nArray elements after inserting new element\n");

// Use unshift() function to aff elements
$vect->unshift(10, 20, 30);

// Display updated vector elements
print_r($vect);

?>

Output:

Original vector:
Ds\Vector Object
(
    [0] => 3
    [1] => 6
    [2] => 1
    [3] => 2
    [4] => 9
    [5] => 7
)

Array elements after inserting a new element
Ds\Vector Object
(
    [0] => 10
    [1] => 20
    [2] => 30
    [3] => 3
    [4] => 6
    [5] => 1
    [6] => 2
    [7] => 9
    [8] => 7
)

Program 2:

<?php

// Create new Vector
$vect = new \Ds\Vector(["geeks", "for", "geeks"]);

echo("Original vector:\n");

// Display the vector elements
print_r($vect);

echo("\nArray elements after inserting new element\n");

// Use unshift() function to aff elements
$vect->unshift("PHP articles");

// Display updated vector elements
print_r($vect);

?>

Output:

Original vector:
Ds\Vector Object
(
    [0] => geeks
    [1] => for
    [2] => geeks
)

Array elements after inserting a new element
Ds\Vector Object
(
    [0] => PHP articles
    [1] => geeks
    [2] => for
    [3] => geeks
)

Reference: http://php.net/manual/en/ds-vector.unshift.php