Why is class list and add not working??

Question

Line 12 gives me and error yet that's how I wrote it in Vscode and it's working

https://sololearn.com/compiler-playground/W0SuAw97u718/?ref=app

Answer 1

there is only one ".nav-dots", hence slidesIcon has the length 1.

and what should happen for slideIndex > 2?

Answer 2

document.querySelectorAll(".nav-dots"); should be changed to document.querySelectorAll(".slide-icon");

And also the Event handler is wrong in so many ways

slideIndex needs to be limited as << slides[slideIndex] >> is bound to be undefined if slideIndex=>3

Take a look

https://sololearn.com/compiler-playground/W7MA69v8x1Sw/?ref=app