(function() {
  'use strict';
  const carouselContainer = document.getElementById('carousel-container');
  const slides = carouselContainer.getElementsByClassName('carousel-slide');
  const images = new Array;
  var slide = 0;
  for (let i = 0; i < slides.length; i++) {
    images.push(slides[i].style.backgroundImage);
  }

  const changeSlide = function() {
    carouselContainer.style.backgroundImage = images[slide];
    slide++;
    console.log(slide);
    if (slide === slides.length) {
      slide = 0;
    }
  }

  setInterval(changeSlide, 2000);
})();