Next Slide 2 - Why nextSlide have value of 0


I am having a little trouble understanding the fundamentals of why the length of the next sibling following the final element is 0.
var currentSlide = $('.active-slide') ;
var nextSlide =;
if(nextSlide.length == 0){
nextSlide = $('.slide').first();
I would like to undertand this further.

Thank you.


Imagine you are going through your ABC's except in JavaScript, you start counting from 0. So A is 0 B is 1, and so forth. Once you get to Z or 25, you must restart to A or 0 or the first element.
This will all make a lot more sense once you take the JavaScript course.


It's because if you reach the end where there's no next slide you reset it to the first slide.


I guess what I'm confused about is why is it length and not value of the next slide?


The value of the next slide is 0, because it is the 1st slide, but in JavaScript you count beginning with 0.

Edit: I understand what you're saying, the if length == 0 part is checking if you have another slide.


@bitrunner65656 Like @cadecodes says, it checks if you have another slide, and if not wraps it around to the beginning.
The reason why it works is because usually nextSlide would be a JavaScript object containing details about nextSlide. If there is no next slide though, that object is empty, so it's length is zero (0).