<template>
  <div>
    <div v-for="(item, index) in items" :key="index">
      {{ getIndex(index) }}: {{ item }}
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      items: ['A', 'B', 'C']
    };
  },
  computed: {
    getIndex() {
      return index => index + this.items.length;
    }
  }
};
</script>

<template>
  <div>
    <div ref="container">
      <div v-for="(item, index) in items" :key="index">
        {{ getIndex(index) }}: {{ item }}
      </div>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      items: ['A', 'B', 'C']
    };
  },
  methods: {
    getIndex(index) {
      const container = this.$refs.container;
      const children = container.children;
      // 根据索引获取元素
      const element = children[index];
      // 获取索引
      const elementIndex = Array.from(children).indexOf(element);
      return elementIndex;
    }
  }
};
</script>