SOURCE

new Vue({
  el: "#app",
  data: {
    password: 9,
    cate: [{
      name: "js", sub: ["vue","jq","react"]
    },
    			 {
    	name: "Databases", sub: ["MySql", "Oracle", "MongoDB"]
    },
  				 {
  		name: "OS", sub: ["macOS", "Windows", "Linux"]
}],
  }
})

<script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
<div id="app">
  <p v-if = " password > 8 " >你的密码大于8位</p>
  <p v-else-if = " password > 1 && password <= 8 ">请输出一个更长的密码</p>
  <p v-else>请输入你的密码</p>
  <ol>
    <li v-for = " item in cate "> {{ item.name }}
      <ul>
        <li v-for = "(key, index) in cate "> {{ key.sub[index] }}
          
        </li>
      </ul>
    </li>
  </ol>
</div>