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JavaScript jQuery Basics (2014) Creating a Simple Lightbox Perform: Part 3

Posted by Grace Ji
Grace Ji
5,402 Points

Why is $overlay.append($image); above $("body").append($overlay);?

The structure is: image in overlay in body.

I don't understand why is $overlay.append($image); above $("body").append($overlay);

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

I don't think the order is important.

Making the overlay complete before adding it to the document body means the browser only has to update once, but in practice doing it the other way would likely happen to fast to see any difference.

Grace Ji
Grace Ji
5,402 Points

Thank you Steven. So unlike CSS cascading from top to bottom in order, in Javascript and jQuery, order doesn't matter?

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

As a general rule, order will be important. But for these specific two statements, the end result will be the same for either order of execution.

But as I pointed out, the intermediate state between them will not affect the browser display in the order shown in the video, but it would if they are reversed.