TYPESCRIPT

html collection of elements to array

const boxes = Array.from(document.getElementsByClassName('box'));

html collection of elements to array

const boxArray = [...document.getElementsByClassName('box')];

html collection to array

var arr = Array.from(htmlCollection);

html collection of elements to array

var boxes = Array.prototype.slice.call(document.getElementsByClassName('box'));

var boxes = [].slice.call(document.getElementsByClassName('box'));

html collection of elements to array

<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>

<script>
    const boxes = document.getElementsByClassName('box');
</script>