gotrade | Golang stock market technical analysis library | Business library

There are several things wrong with your code. For example, you're checking for a classname called active-slide, but nothing in your code sets a class with that name. If you're copying and pasting code from other sources without taking some time to understand it, it may be impossible to debug.

Instead of checking for the existence of a class that doesn't exist, you can instead check for which slide number you're on, and check if you're on the first or last slide. You also need to run this code after slide transitions, not once at the end of your program as you've shown in the Codepen. Here's an example of the working Javascript checking for slideIndex instead of a class: