Lazy loading script for images and backgrounds

lazyLoading.html

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
    (function(g,f,j,i,h){$(window).on("load",function(){i=0;$("["+g+"]").each(function(){function a(b){h=b.attr(f);if(b.attr(g)=="style"){b.css("background-image","url("+h+")")}else{b[0].src=h}}setTimeout(a,++i*j,$(this))})})})(
        "data-lazyLoading", // attribute for type
        "data-src",         // attribute for src
        100                 // delay in milliseconds
    );
</script>
<img data-lazyLoading data-src="https://frydlewicz.pl/photo/Warszawa/DSC07655.jpg" alt>
<div data-lazyLoading="style" data-src="https://frydlewicz.pl/photo/Warszawa/DSC07644.jpg"></div>