Functions to make scripts async and defer on WordPress Seventeen Theme

functions.php

function add_defer_attribute($tag, $handle) {
	// add script handles to the array below
	$scripts_to_defer = array(
		'html5', 
		'jquery',
		'jquery-migrate',
		'wp-embed',
		'twentyseventeen-skip-link-focus-fix',
		'jquery-scrollto',
		'twentyseventeen-global',
		'twentyseventeen-navigation',
		'comment-reply');
	
	foreach($scripts_to_defer as $defer_script) {
	   if ($defer_script === $handle) {
		  return str_replace(' src', ' defer="defer" src', $tag);
	   }
	}
	return $tag;
 }

 function add_async_attribute($tag, $handle) {
	// add script handles to the array below
	$scripts_to_async = array(
		'jquery',
		'jquery-core',
		);
	
	foreach($scripts_to_async as $async_script) {
	   if ($async_script === $handle) {
		  return str_replace(' src', ' async="async" src', $tag);
	   }
	}
	return $tag;
 }
 add_filter('script_loader_tag', 'add_defer_attribute', 10, 2);
 add_filter('script_loader_tag', 'add_async_attribute', 10, 2);