js how to load a image code example

Example 1: javascript on image load

window.onload = function () {

        var logo = document.getElementById('sologo');

        logo.onload = function () {
            alert ("The image has loaded!");		
        };

        setTimeout(function(){
            logo.src = 'https://edmullen.net/test/rc.jpg';         
        }, 5000);
    };

Example 2: js load img

var elements = [];
function loaded(){
  console.log("you have loaded an image");
}
CreateFileFrom("your/dir/here/img.png");

function CreateFileFrom(dir){

  		/* defining runtime variables */
	  		var extension                        =   dir.split('.').pop();
	  		var keys                             =   {"png":"IMG","jpg":"IMG","jpeg":"IMG",
	  												  "js":"SCRIPT","json":"SCRIPT",
	  												  "mp3":"AUDIO","wav":"AUDIO"};
	  	    var obj                              =   document.createElement(keys[extension]) || {};
	  	    obj.src                              =   dir;
	  	    
	  	/* onload function called when the resource is loaded */
	  	    obj.onload                           =   (e) => {

	  	    	elements.push(e.path[0]);
	  	    	loaded()
	  		}

  		/* make sure that the data is compitable */
  			if(keys[extension]==null){console.error("not supported media type "+extension);return;}
  	}