I watched a tutorial where they showed that appending ?${new Date().getTime()}to the value of src attribute in the image tag, updates the current image with the new image.
I came across this question, where the first answer to the question has followed the same technique.
Could someone please explain to me the rationale behind the working of this particular technique. Thanks!
Simplest explanation is that the browser (and often the server) will cache items in memory to decrease page load times. Therefore, if you have a dozen pages that all are referencing /images/logo.png, the image is downloaded once and stored so that it can be re-used on each page. Efficient, right?
Anyways, sometimes images change and you don't want that to happen, so what you do is change the name of the file. For example, /images/logo.png?15, /images/logo.png?16, /images/logo.png?17, etc. The browser no longer attempts to use the cached image because the query is actually different.
The code snippet you've included simply includes the current time to the name of the file in order to make it unique.