Question

I’ve included code in my project I don’t understand.

// where dImage is an existing image entity on my page
$("<img>").attr("src", $(dImage).attr("src")).load(function() {

1) what does $("<img>") mean? I would assume it means all image entities in the DOM, but when i tried to $("<img>").attr("woah","baby"); and then inspect the dom, there’s no trace of my custom attribute. why?

2) why is this value undefined in load callback? $("<img>").attr("src"); = undefined.

3) what would this code be expected to do?

Insight greatly appreciated. What is the use of this statement?

Answer 1

1) No. $('<img>') creates a new image element, which will get the src obtained from the dImage element. For “all image entities in the DOM”, you’d do $('img'), just like a CSS selector.

2) Which value? $("<img>").attr("src"); = undefined. is invalid code. If you actually mean the src of $("<img>"), then again it’s because $("<img>") creates a new img element.

3) Create a new image, assign the src, and attach a load event handler that is invoked when the image is finished loading.