PHP Manual: Returns the sum of all values in the deque

public intfloat Ds\Deque::sum()

Returns the sum of all values in the deque.

Note:
Arrays and objects are considered equal to zero when calculating the sum.

This function has no parameters.

The sum of all the values in the deque as either a float or int depending on the values in the deque.

Example #1 Ds\Deque::sum integer example

<?php
$deque = new \Ds\Deque([1, 2, 3]);
var_dump($deque->sum());
?>

The above example will output something similar to:

int(6)

Example #2 Ds\Deque::sum float example

<?php
$deque = new \Ds\Deque([1, 2.5, 3]);
var_dump($deque->sum());
?>

The above example will output something similar to:

float(6.5)