左右键操作轮播图 以及小圆点切换轮播图

好的，关于左右键操作轮播图和小圆点切换轮播图的实现方法，可以参考以下代码：

HTML代码：

<div class="slider">
  <ul class="slides">
    <li><img src="img/slide1.jpg"></li>
    <li><img src="img/slide2.jpg"></li>
    <li><img src="img/slide3.jpg"></li>
  </ul>
  <a class="prev" onclick="prevSlide()">❮</a>
  <a class="next" onclick="nextSlide()">❯</a>
  <div class="dots">
    <span class="dot" onclick="currentSlide(1)"></span>
    <span class="dot" onclick="currentSlide(2)"></span>
    <span class="dot" onclick="currentSlide(3)"></span>
  </div>
</div>

CSS代码：

.slider {
  width: 600px;
  height: 400px;
  position: relative;
  overflow: hidden;
}

.slides {
  width: 1800px;
  height: 400px;
  padding: 0;
  margin: 0;
  list-style: none;
  position: absolute;
  top: 0;
  left: 0;
}

.slides li {
  float: left;
  width: 600px;
  height: 400px;
}

.prev, .next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  font-size: 30px;
  display: block;
  cursor: pointer;
  z-index: 1;
}

.prev {
  left: 10px;
}

.next {
  right: 10px;
}

.dots {
  text-align: center;
  margin-top: 10px;
}

.dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: #bbb;
  margin: 0 5px;
  cursor: pointer;
}

.active {
  background-color: #717171;
}

JavaScript代码：

var slides = document.querySelector('.slides');
var slideIndex = 1;
var dots = document.querySelectorAll('.dot');

function showSlide(n) {
  var slidesList = slides.querySelectorAll('li');
  if (n > slidesList.length) {
    slideIndex = 1;
  }
  if (n < 1) {
    slideIndex = slidesList.length;
  }
  for (var i = 0; i < slidesList.length; i++) {
    slidesList[i].style.display = 'none';
  }
  slidesList[slideIndex - 1].style.display = 'block';
  for (var j = 0; j < dots.length; j++) {
    dots[j].classList.remove('active');
  }
  dots[slideIndex - 1].classList.add('active');
}

function prevSlide() {
  showSlide(slideIndex -= 1);
}

function nextSlide() {
  showSlide(slideIndex += 1);
}

function currentSlide(n) {
  showSlide(slideIndex = n);
}

showSlide(slideIndex);

setInterval(function() {
  nextSlide();
}, 3000);

这个代码同时实现了左右键切换轮播图和小圆点切换轮播图，左右键通过onClick事件触发prevSlide()和nextSlide()函数，小圆点通过onClick事件触发currentSlide()函数。每隔3秒钟自动切换图片。