Get the height of the display, based on body - then on the lowest element within the body

getHeight.ts

/**
 * Get the height of the display, based on body height, then the lowest element within it
 */
function getHeight(): number {
	var i = 0,
		body = document.body,
		style = body.style,
		elements = document.querySelectorAll("body *"),
		best = body.offsetHeight + (parseInt(style.marginTop, 10) || 0) + (parseInt(style.marginBottom, 10) || 0);;

	while (i < elements.length) {
		let element = elements[i++],
			bottom = element.getBoundingClientRect().bottom + (parseInt(getComputedStyle(element).marginBottom, 10) || 0);

		if (bottom > best) {
			best = bottom;
		}
	}

	return best;
}