How do I get img src?

Question

I'm not sure why, but I'm having trouble getting image src value? Here's my HTML:

<div id="gallery">
 <img src="css/images/cat.jpg" id="main-img">
</div>

Here's my javascript:

window.setInterval(function() {
    var currentImage = $("#main-img").attr("src");
    window.alert(currentImage);
}, 5000);

But I keep getting undefined whenever the alert comes up.

Answer 1

Just as a footnote as much as anything else.

For this jQuery :

setInterval(function() {
    var currentImage = $("#main-img").attr("src");
    window.alert(currentImage);
}, 5000);

the equivalent in vanilla javascript is:

setInterval(function(){
    var currentImage = document.querySelector('#main-img').getAttribute('src');
    window.alert(currentImage);
}, 5000);