autoplay video html not working code example

Example 1: iframe youtube not working

<iframe width="560" height="315" src="https://www.youtube.com/embed/ZwKhufmMxko" frameborder="0" allowfullscreen></iframe>

Example 2: html video tag autoplay not working

<script type="text/javascript">
	window.onload= function(){
	var x = document.getElementById("home-video").play();
	}