老师我用ES6语法自己重新写了一次麻烦帮忙看下有什么需要改进

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="css/reset.css">
    <link rel="stylesheet" href="css/slider.css">
</head>

<body>
    <div class="slider" id="slider">
        <div class="slider-item-container">
            <div class="slider-item">
                <a href="###" class="slider-link">
                    <img src="img/1.jpg" alt="slider" class="slider-img">
                </a>
            </div>
            <div class="slider-item">
                <a href="###" class="slider-link">
                    <img src="img/2.jpg" alt="slider" class="slider-img">
                </a>
            </div>
            <div class="slider-item">
                <a href="###" class="slider-link">
                    <img src="img/3.jpg" alt="slider" class="slider-img">
                </a>
            </div>
            <div class="slider-item">
                <a href="###" class="slider-link">
                    <img src="img/4.jpg" alt="slider" class="slider-img">
                </a>
            </div>
            <div class="slider-item">
                <a href="###" class="slider-link">
                    <img src="img/5.jpg" alt="slider" class="slider-img">
                </a>
            </div>
        </div>


    </div>
    <button id="prev">prev</button>
    <button id="next">next</button>
    <script>
        class Slider {
            constructor(el, options = {}) {
                Object.assign(this, {
                    initIndex: 0,
                    speed: 300,
                    hasIndicator: false
                }, options);
                this.options = options;
                this.el = el;
                this.itemContainer = el.querySelector('.slider-item-container');
                this.items = this.itemContainer.children;
                this.distancePerSlider = this.items[0].offsetWidth;
                this.minIndex = 0;
                this.maxIndex = this.items.length - 1;
                this.index = this._adjustIndex(this.options.initIndex);

                this.move(this.getDistanceByIndex(this.index));
                if (this.options.hasIndicator) {

                    this._createIndicators();
                    this._setIndicatorsActive(this.index);
                }
            }

            to(index) {
                this.index = index;
                this._setTransitionSpeed(this.options.speed);
                this.move(this.getDistanceByIndex(this.index));
                const that = this;
                this.itemContainer.addEventListener('transitionend',()=>{
                    that._setTransitionSpeed(0);
                },false);
                if(this.options.hasIndicator){
                    this._setIndicatorsActive(this.index);
                }
            }

            prev() {
                this.to(this.index - 1);
            }

            next() {
                this.to(this.index + 1);
            }

            _setTransitionSpeed(speed){
                this.itemContainer.style.transitionDuration = speed + 'ms';
            }

            _adjustIndex(index) {
                if (index < this.minIndex) {
                    index = this.minIndex;
                } else if (index > this.maxIndex) {
                    index = this.maxIndex
                }
                return index;
            }

            move(distance) {
                this.itemContainer.style.transform = 'translate3d(' + distance + 'px,0,0)'
            }

            getDistanceByIndex(index) {
                return -index * this.distancePerSlider;
            }

            _createIndicators() {
                const indicatorContainer = document.createElement('div');
                let html = '';
                indicatorContainer.className = 'slider-indicator-container';
                for (let i = 0; i <= this.maxIndex; i++) {
                    html += '<span class="slider-indicator"></span>';
                }

                indicatorContainer.innerHTML = html;
                this.el.appendChild(indicatorContainer);
            }

            _setIndicatorsActive(index) {
                this.indicators = this.indicators || this.el.querySelectorAll('.slider-indicator');
                for (let i = 0; i < this.indicators.length; i++) {
                    this.indicators[i].classList.remove('slider-indicator-active');
                }
                this.indicators[index].classList.add('slider-indicator-active');
            }
        }
    </script>
    <script>
        const slider = new Slider(document.getElementById('slider'), {
            initIndex: 2,
            speed: 300,
            hasIndicator: true
        });
        document.getElementById('prev').addEventListener('click', () => {
            slider.prev();
        }, false);
        document.getElementById('next').addEventListener('click', () => {
            slider.next();
        }, false);
    </script>
</body>

</html>