Detect image load by jQuery

<img src="http://site.com/image.png" />

I change src of this image on .click event.

There can be loaded more than 20 different images, after changing src.

1) How do I kno开发者_StackOverflow社区w, was image already loaded (should be cached) or it has to be loaded?

2) How to run two different functions, for loaded and not?

Thanks.

You need to attach an event handler for the load event:

Update 2017:

$('img').on('load', function() {
    alert('new image loaded: ' + this.src);
});

Plain JS/DOM:

imgNode.onload = () => {
    alert('new image loaded: ' + this.src);
};