vue filters过滤

<template>
  <div class="filters">
    <h1 v-text="filtersTitle"></h1>
    <input v-model="filtersText"/>
    <div>{{filtersText | filtersTextChange}}</div>
  </div>
</template>
<script>
  let vm = {};
  export default {
    data() {
      vm = this;
      return {
        filtersTitle: 'vue过滤器学习，filters',
        arrayList: [
          {
            "code": "1",
            "value": "北京市"
          },
          {
            "code": "2",
            "value": "上海市"
          },
          {
            "code": "3",
            "value": "广州市"
          },
          {
            "code": "4",
            "value": "深圳市"
          },
          {
            "code": "5",
            "value": "杭州市"
          },
          {
            "code": "6",
            "value": "天津市"
          },
          {
            "code": "7",
            "value": "西安市"
          },
          {
            "code": "8",
            "value": "武汉市"
          },
          {
            "code": "9",
            "value": "长沙市"
          }
        ],
        filtersText: '1',
      }
    },
    filters: {
      filtersTextChange: function (dataStr) {
        let arrayList = vm.arrayList;
        let value = '没有这个城市 ';
        for (let b of arrayList) {
          if (b.code == dataStr) {
            value = b.value;
            break;
          }
        }
        return value;
      }
    }
  }
</script>