Twig Access Array Index?

Just before posting this I realized, that's exactly what you can do, but as I didn't find the answer anywhere in the docs or google (correct me if I'm wrong), I've posted this anyway.

{{numbers[0]}} 

The answer of Adam, is correct, only to make it clear and improve, you can have access directly to array index

{{ myArray[0] }}

if you need to access in a loop

{% set arrayOfItems = ['ZERO', 'ONE'] %}
{% set myArray = ['APPLE', 'ORANGE'] %}
{% for oneItem in arrayOfItems %}
    <p>{{ oneItem }} equals {{ myArray[loop.index0] }}</p>
{% endfor %}

in this example I used an array inside a non related loop so the result is:

ZERO equals APPLE
ONE equals ORANGE

Thats actually something what doesnt work for me when using Twig with shopware 6. I try to access an object like

{{ page.cart.lineItems.elements[0].quantity }}

what will lead into a parsing error of the Twig Template

I can use

{{ page.cart.lineItems.elements | first }}

to get the first Element, but dont know how i can then access a property of this first element