Cannot set property 'src' of null

Question

I am trying to rotate an image using javascript and I was trying some code I found on adobes website that does what I was looking for. When I run it it gives me the error: Unca

Answer 1

Your script is loaded before the body of your page, so the rotator element is not found. Remove the var rotator = ... line and put it inside the changeImage function instead:

(function () {
    var rotator;
    var rotatedImageId = 'rotator';           // change to match your HTML
    var imageDir = 'images/';
    var delayInSeconds = 5;
    // list image names
    var images = ['image2.jpg', 'image3.jpg', 'image4.jpg', 'image1.jpg'];

    // don't change below this line
    var num = 0;
    var changeImage = function () {
        if (!rotator)
            rotator = document.getElementById(rotatedImageId);
        if (!rotator)
            return;

        var len = images.length;
        rotator.src = imageDir + images[num++];
        if (num == len) {
            num = 0;
        }
    };
    setInterval(changeImage, delayInSeconds * 1000);
})();