Sequence Add Class

sequence-addclass.js

var sequenceAddClass = function(els) {
	function addClassWithTimeout(i, el) {
		var t = setTimeout(function() {
			clearTimeout(t);
			el.className = el.className + "addsomeclass";
		}, i * 200);
	}
	for (var i = 0; i < els.length; i++) {
		addClassWithTimeout(i, els[i]);
	}
};

var elements = document.querySelectorAll('img');
sequenceAddClass(elements);