求助：将以下ES5格式代码转换为ES6格式！！！

function slider(id){

    //属性

    //  1. 通过id获取元素对象（大盒子）

    this.bigbox = document.getelementbyid(id);

   //2. 获取出大盒子中的所有图片（数组）

   this.ullis = this.bigbox.children[0].children;

    //3. 统计图片数量（数组.length)

    this.num = this.ullis.length;

    //4. 获取所有的小圆点

    this.ollis = this.createelement();

    //5. 设置轮播的当前下标

    this.indexa = 0;

    //8. 获取文字信息的div

    this.div = $id('msg');

    this.slide();

    //6. 获取左按钮

    this.ltbtn = $id('ltbtn');

    //7. 获取右按钮

    this.rtbtn = $id('rtbtn');

    this.addevent();

    //9. 计时器

    this.timer = null;

    this.autoplay();

}

slider.prototype.createelement = function(){

    //1. 左按钮

    var spanleft = document.createelement('span');

    spanleft.id = 'ltbtn';

    spanleft.innerhtml = '<';

    this.bigbox.appendchild(spanleft);

    //2. 右按钮

    var spanright = document.createelement('span');

    spanright.id = 'rtbtn';

    spanright.innerhtml = '>';

    this.bigbox.appendchild(spanright);

    //3. ol li

    var arr = []; //放置li

    //创建ol

    var ol = document.createelement('ol');

    //创建li

    for(var i = 0;i < this.num;i ++){

        var li = document.createelement('li');

        arr.push(li);

        ol.appendchild(li);

    }

    this.bigbox.appendchild(ol);

    //4. 信息框(div)

    var div = document.createelement('div');

    div.id = 'msg';

    this.bigbox.appendchild(div);

    return arr;

}

slider.prototype.slide = function(){

    //1》图片轮播

       // 遍历所有的图片，display - none

   for(var i = 0;i < this.num;i ++){

       this.ullis[i].style.display = 'none';

   }

       // 当前图片 display-block

   this.ullis[this.indexa].style.display = 'block';

   //2》 小圆点

       //遍历所有的小圆点，background=red

   for(var i = 0;i < this.num;i ++){

       this.ollis[i].style.backgroundcolor = 'red';

   }

       //当前小圆点，background = blue

   this.ollis[this.indexa].style.backgroundcolor = 'blue';

       //信息框 = img中的alt属性

   this.div.innerhtml = this.ullis[this.indexa].firstelementchild.firstelementchild.alt;

}

slider.prototype.addevent = function(){

    var that = this;

    //  1. 左按钮 -- 点击事件-- 改变当前下标的值，调用轮播方法

    this.ltbtn.onclick = function(){

        that.indexa --;

        if(that.indexa == -1){

            that.indexa = that.num - 1;

        }

        that.slide();

    }

    //2. 右按钮 -- 点击事件--改变当前下标的值，调用轮播方法

    this.rtbtn.onclick = function(){

        that.indexa ++;

        if(that.indexa === that.num){

            that.indexa = 0;

        }

        that.slide();

    }

    //3. 遍历小圆点--移入事件--改变当前下标 的值，调用轮播方法

    for(var i = 0;i < this.num;i ++){

        //记录下标

        this.ollis[i].index = i;

        this.ollis[i].onmouseenter = function(){

            that.indexa = this.index;

            that.slide();

        }

    }

}

slider.prototype.autoplay = function(){

    var that = this;

    this.timer = setinterval(function(){

        that.indexa ++;

        if(that.indexa === that.num){

            that.indexa = 0;

        }

        that.slide();

    },3000)

    //移入大盒子，停止自动轮播

    this.bigbox.onmouseenter = function(){

        clearinterval(that.timer);

    }

    //移出大盒子，开启自动轮播

    this.bigbox.onmouseleave = function(){

        that.autoplay();

    }

}

//工具箱

function $id(id){

    return document.getelementbyid(id);

}