删除语法链写法

src/components/SliderMenu.vue

@@ -1,7 +1,7 @@
 <template>
   <transition :name="customize ? '' : 'menu-collapse'">
     <el-menu v-if="!customize" class="el-menu-vertical-demo custom-menu" @open="handleOpen"
-    :default-active="currentMenuItem?.index" :default-openeds="defaultOpeneds"
+    :default-active="currentMenuItem && currentMenuItem.index" :default-openeds="defaultOpeneds"
       @close="handleClose" @select="handleSelect" :collapse="isCollapse" :collapse-transition="true"
       >
       <div style="height: 100%;padding: 0 0 20px;box-sizing: border-box;">
@@ -21,7 +21,7 @@
           <el-submenu v-if="item.children"  :key="item.index" :index="item.index">
             <template slot="title">
               <SvgIcon1 :iconPath="require(`@/assets/menu/${item.icon}.svg`)" defaultColor="#8A9099"
-                activeColor="#006AFF" :isActive="item.index == currentMenuItem?.index?.substring(0,1) && isCollapse" />
+                activeColor="#006AFF" :isActive="item.index == currentMenuItem && currentMenuItem[index].substring(0,1) && isCollapse" />
               <span class="title_text" >{{ item.title }}</span>
             </template>
             <el-menu-item style="padding: 0 22px 0 32px;" v-for="subItem in item.children" :key="subItem.index"
@@ -32,7 +32,7 @@
           <el-menu-item v-else :index="item.index"  :key="item.index" @click="handleSelect(item.index, [item.index], item)">
               <div class="flex">
                 <SvgIcon1 :iconPath="require(`@/assets/menu/${item.icon}.svg`)" defaultColor="#8A9099"
-                  activeColor="#006AFF" :isActive="item.index == currentMenuItem?.index" />
+                  activeColor="#006AFF" :isActive="item.index == currentMenuItem[index]" />
                 <span class="title_text" slot="title">{{ item.title }}</span>
               </div>
           </el-menu-item>