地址栏传多个参数筛选、参数更新

背景：页面数据由后台渲染
需求：筛选条件课程类目、是否收费、课程类型（线上、线下），三个参数，要求点击对应选项通过地址栏传参筛选数据。

 <div class="filterBox">
        <div class="cate-tab flex_between">
            <div class="cate-item pointer" data-CategoryId="">全部课程</div>
            @foreach (var item in CourseCategoryList)
            {
                <div data-CategoryId="@item.CategoryId" class=" cate-item pointer"> @item.CategoryName</div>
            }
        </div>
        <div class="opt-tab flex_between">
            <a class="isFree pointer active" data-IsFree="">全部</a>
            <a class="isFree pointer" data-IsFree="0">付费</a>
            <a class="isFree pointer" data-IsFree="1" >免费</a>
            <div class="line"></div>
            <a class="type pointer" data-Type="">全部</a>
            <a class="type pointer" data-Type="1">线上</a>
            <a class="type pointer" data-Type="2">线下</a>
        </div>
    </div>

   getUrlParams();         //获取地址栏参数，存成对象
    initStyle('IsFree');      //根据地址栏参数高亮当前页面所选的筛选项
    initStyle('CategoryId');
    initStyle('Type');
    $('.cate-item').on('click', (e) => {        //选项点击事件，更新对应参数值，并跳转
        changeParams('CategoryId',e)
    })
    $('.type').on('click', (e) => {
        changeParams('Type',e)
    })
    $('.isFree').on('click', (e) => {
        changeParams('IsFree',e)
    })

function getUrlParams() {
    let paramsArr = paramString.replace('?','').split('&')
    if(paramString){
        paramsArr.map(i=>{
            let key = i.split('=')[0]
            let value = i.split('=')[1]
            paramsObj[key] = value
            return i
        })   
    }
}

function initStyle(key){
    let $keyDom = $(`[data-${key}]`)
    if(key in paramsObj){
        for(let i=0;i<$keyDom.length;i++) {
            $keyDom.eq(i).removeClass('active')
            if($keyDom.eq(i).attr(`data-${key}`)===paramsObj[key]){
                $keyDom.eq(i).addClass('active')
            }
        }
    }else{
        $(`[data-${key}=""]`).addClass('active')
    }
}
function changeParams(dataKey, e) {
    let key = $(e.currentTarget).attr(`data-${dataKey}`)
    if (!paramString) {                  //url无参数
        location.href = location.pathname + '?' + dataKey + '=' + key   //加第一个参数
    } else if (dataKey in paramsObj) {   //有参数，点击的参数是否已有
        if (key) {                       //已有且新选属性值key不为空则替换
            paramsObj[dataKey] = key     
        } else {                         
            delete paramsObj[dataKey]    //key为空则删除该属性
        }
        //更新后将已有参数拼成url
        let keyArr = Object.keys(paramsObj)
        let valArr = Object.values(paramsObj)
        let pArr = []
        for (let k = 0; k < keyArr.length; k++) {
            pArr[k] = keyArr[k] + '=' + valArr[k]
        }
        let newLink = ''
        if (pArr.length > 0) { 
            newLink = '?' + pArr.join('&')  //如果有参数 拼起来
        }
        location.href = location.pathname + newLink   //没有，添加在后面
    } else {
        location.href = location.href + '&' + dataKey + '=' + key
    }
}