vue常用方法

<div class="arror" v-if="item.supports.length > 2">
                                {{item.supports.length}}个活动<i class="iconfont">&#xe61a;</i>
                            </div>

<li class="shop_supports_item" v-for="(itemSp,index) in item.supports" v-if="index < 2">
                                    <span class="shop_icon_sup" :class="classMap[item.supports[index].type]"></span>
                                    <span class="supports_text">{{itemSp.description}}</span>
                                </li>