Vue realizes cascading selection of provinces, cities and districts

<!--PC code-->
 <el-form :inline="true" :model="addressForm">
        <el-form-item label="省" label-width="100px" prop="province">
          <el-select v-model="addressForm.province" placeholder="Please select" style="width:250px" @change="bindProvinceChange">
          <!-- :value="item.value+'|'+item.label" If you want to get both the number and the province name, the value assignment can be written like this, and then cut with |. If you don't need to get both, just assign one. -->
            <el-option v-for="item in provinceList" :label="item.label" :value="item.value+'|'+item.label"></el-option>
          </el-select>
        </el-form-item>
        <br />
        <el-form-item label="市" label-width="100px" prop="city">
          <el-select v-model="addressForm.city" placeholder="Please select" style="width:250px" @change="bindCityChange">
            <el-option v-for="item in cityList" :label="item.label" :value="item.value+'|'+item.label"></el-option>
          </el-select>
        </el-form-item>
        <el-form-item label="District/County" label-width="100px" prop="county">
          <el-select v-model="addressForm.county" placeholder="Please select" style="width:250px" @change="bindCountyChange">
            <el-option v-for="item in countyList" :label="item.label" :value="item.value+'|'+item.label"></el-option>
          </el-select>
        </el-form-item>
        <el-form-item label="Street/Town" label-width="100px" prop="street">
          <el-input type="textarea" :rows="3" resize="none" placeholder="Please enter street information" v-model="addressForm.street"
            style="width:250px">
          </el-input>
        </el-form-item>
</el-form>

var app = new Vue({
      el: '#app',
       data: {
    addressForm: {
           province: '',
           city: '',
           county: '',
           street: ''
         },
         // The data of provinces, cities and districts are placed in another file. I am importing the provinceList directly from another file: areaList.provinceList,
         cityList: [],
         countyList: []
  },
  methods:{
   // Province bindProvinceChange(vals) {
         // Get the unique number corresponding to the province console.log('data========>', vals)
           let arr = vals.split('|')
           this.addressForm.province = arr[1]
           this.addressForm.city = '';
           this.addressForm.county = '';
           this.addressForm.street = '';
           // Get the corresponding city this.cityList = this.addrInit(2, areaList.cityList, arr[0]);
         },
         // City bindCityChange(vals) {
           console.log('vals------->', vals)
           this.addressForm.county = '';
           this.addressForm.street = '';
           let arr = vals.split('|')
           this.addressForm.city = arr[1]
            // Get the corresponding district and county this.countyList = this.addrInit(4, areaList.countyList, arr[0]);
         },
         //District and county bindCountyChange(vals) {
           console.log('vals------======>', vals)
           this.addressForm.street = '';
           let arr = vals.split('|')
           this.addressForm.county = arr[1]
         },
         // Convert the object to an array transArray(obj) {
           let arr = [];
           for (let i in obj) {
             arr.push(obj[i]);
           }
           return arr;
         },
         /**
          * Encapsulation method - get the corresponding province, city, and district* @param {number} num The number of digits to be intercepted* @param {*} list The array to be queried* @param {*} str The string to be intercepted* @returns
          */
         addrInit(num, list, str) {
           let strSub = str.substr(0, num);
           let arr = this.transArray(list);
           let newArr = arr.filter(function (val, index, arr) {
             let newStr = val.value.substr(0, num);
             return newStr == strSub;
           });
           return newArr;
         },
  }
 })