jq removeClass 失效 什么情况？

Question

if( _self.$refs.confirmed.style.display==="block"){
  _self.$refs.confirmed.style.display="none";
  $(".drop-down__arrow").removeClass("drop-down__arrow-down");                           
  b.target.className="drop-down__arrow";
}else {
  _self.$refs.confirmed.style.display="block";
  _self.$refs.unconfirmed.style.display="none";                         
  $(".drop-down__arrow").removeClass("drop-down__arrow-down");
  b.target.className="drop-down__arrow drop-down__arrow-down";
}

需求很简单

但最后发现 没有生效 看上面那个箭头 没有变

Answer 1

都用了vue了为什么不这么写啊

//伪代码
<li v-on:click="changeIndex" v-for="{item, index} in items">
    <arrow :class="{index==flagIndex?rop-down__arrow-down:''}"> </arrow>
    <div :class="{index==flagIndex?show:hide}"> <div>
</li>