PHP | Ds\Vector shift() Function

The Ds\Vector::shift() function is an inbuilt function in PHP which is used to remove the first element from the vector and return it.

Syntax:

mixed public Ds\Vector::shift( void )

Parameters: This function does not accept any parameter.

Return Value: This function returns the value at index 0.

Exception: This function throws UnderflowException if vector is empty.

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

Program 1:

<?php

// Declare an Vector
$vect = new \Ds\Vector(["geeks", "of", "geeks"]);

echo("First element in the vector:\n");

// Use shift() function to remove first
// element from vector and display it
var_dump($vect->shift());

?>

Output:

First element in the vector:
string(5) "geeks"

Program 2:

<?php

// Declare an Vector
$vect = new \Ds\Vector([1, 2, 3, 4, 5, 6]);

// Use shift() function to remove first
// element from vector and display it
var_dump($vect->shift());

var_dump($vect->shift());

var_dump($vect->shift());

var_dump($vect->shift());

?>

Output:

int(1)
int(2)
int(3)
int(4)

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