How do I check if file exists in jQuery or pure JavaScript?

Question

How do I check if a file on my server exists in jQuery or pure JavaScript?

Answer 1

First creates the function

$.UrlExists = function(url) {
	var http = new XMLHttpRequest();
    http.open('HEAD', url, false);
    http.send();
    return http.status!=404;
}

After using the function as follows

if($.UrlExists("urlimg")){
	foto = "img1.jpg";
}else{
	foto = "img2.jpg";
}

$('').attr('src',foto);