Osman Osman - 1 year ago 35
Javascript Question

How to check if an image URL has been inputted into a Prompt - JavaScript

$(function() {
$(".upload").click(function() {
link = prompt("Paste a background image url");
if (link == null) {
else {
div = document.createElement('div');
$(div).addClass("images").html('<img src="' + link + '">');

Above is the code that I am currently using which asks the user to input an Image URL of which a new div is created with the inputted image within.

If the user inputs a bit of text (or something that isn't an image URL), the div would still be created though the image tag would read:

How do I check to see if the user inputs an image URL?

Answer Source

You COULD just do:

 var extension = id.substr(link.length - 3); // get last 3 chars from the string
 if ((extension == "bmp") || (extension == "png") || ... you get the idea ) {
 do right stuff
 do wrong stuff

But, you have to take into consideration before displaying the link, that it could also be trying do some XSS, so take the proper considerations