const boxes = Array.from(document.getElementsByClassName('box'));
const boxArray = [...document.getElementsByClassName('box')];
var boxes = Array.prototype.slice.call(document.getElementsByClassName('box')); var boxes = [].slice.call(document.getElementsByClassName('box'));
<div class="box"></div> <div class="box"></div> <div class="box"></div> <div class="box"></div> <script> const boxes = document.getElementsByClassName('box'); </script>