Javascript: Carousel active dots and left-right buttons

Question

I am beginner level javascript developer. I have decide to make carousel by using pure Javascript. I successfully manage to slide the carousel. I have decided to make active dots(also clickable), i want the dots background colour change when slide happen and left-right button. I have created the dots but I don't know how to implement the dots in my slide function as well left and right button. Here is my code:

Also please explain me the logic. Thank you

 const images = document.getElementById('imgs'); const allImages = document.querySelectorAll('#imgs img'); const leftBtn = document.getElementById('left'); const rightBtn = document.getElementById('right'); let index = 0; function run() { const dot = [...document.getElementsByClassName('star')]; index++; if (index > allImages.length - 1) { index = 0 dot.forEach(i => i.classList.add('active')) } imgs.style.transform = `translateX(${-index * 500}px)` } const dot = allImages.forEach(i => { const elem = document.createElement('div'); elem.classList.add('star'); document.body.appendChild(elem) }) let x = setInterval(run, 2000); images.onmouseover = () => { clearInterval(x) } images.onmouseout = () => { x = setInterval(run, 2000); }

 *{ box-sizing: border-box; } body { margin: 0; display: flex; justify-content: center; align-items: center; min-height: 100vh; } .carousel { overflow: hidden; width: 500px; height: 500px; box-shadow: 2px 2px 5px rgba(0, 0, 0, .3); border-radius: 5px; } .image-container { display: flex; transition: transform 300ms linear; transform: translateX(0); } img { width:500px; height: 500px; object-fit: cover; } .star{ cursor: pointer; height: 15px; width: 15px; margin: 0 10px; border-radius: 50%; display: inline-block; transition: background-color 0.6s ease; background-color: #eeeeee; } .star.active{ background-color: red; } button{ cursor: pointer; position: relative; font-size: 18px; transition: 0.6s ease; user-select: none; height: 50px; width: 40px; display: flex; justify-content: center; align-items: center; align-content: center; top: calc(50% - 25px); } button:hover { background-color: rgba(0,0,0,0.8); }; button.left { border-radius: 3px 0 0 3px; right: 0; } button.left { border-radius: 3px 0 0 3px; left: 0; }

 <button id="left">&#10094;</button> <button id="right">&#10095;</button> <div class="carousel"> <div class="image-container" id="imgs" > <img src="https://images.unsplash.com/photo-1599736375341-51b0a848f3c7?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt=""> <img src="https://images.unsplash.com/photo-1516026672322-bc52d61a55d5?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt=""> <img src="https://images.unsplash.com/photo-1573081586928-127ecc7948b0?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt=""> <img src="https://images.unsplash.com/flagged/photo-1572850005109-f4ac7529bf9f?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt=""> </div> </div>

Answer 1

You were close to the result. In your run function, you just have to change the class of the current active dot and set the new one to active. I renamed your dot variable to dots for the sake of comprehension.

function run() {
  const dots = [...document.getElementsByClassName('star')];
  index++;


  if (index > allImages.length - 1) {
    index = 0
  }
  
  dots.forEach((dot, i) => {
    if (dot.classList.contains('active')) dot.classList.remove('active');
    if (i === index) dot.classList.add('active'));
  }
  imgs.style.transform = `translateX(${-index * 500}px)`

}