JS如何修改数组对象的Key和指定的值

 /**/
    var Arrydata = [{name:'Lily',age:18},{name:'BKqq',age:22}]
    //旧key到新key的映射
    var keyMap = {
      // id: "value",
      name: "label",
      age: "value"
    };
    for (var i = 0; i < Arrydata.length; i++) {
      var obj = Arrydata[i];
      for (var key in obj) {
        var newKey = keyMap[key];
        if (newKey) {
          obj[newKey] = obj[key];
          delete obj[key];
        }
      }
    }
    console.log(Arrydata,'修改后数组对象---')

var stooges = [
            {label:1,value:1,placeCode: 'sh', stock_code: 40},
            {label:1,value:1,placeCode: 'sh', stock_code: 50},
            {label:1,value:1,placeCode: 'sz', stock_code: 60,status:1},
            {label:1,value:1,placeCode: 'sz', stock_code: 39,status:1}
        ];
  for(var i=0;i<stooges.length;i++){
      stooges[i].placeCode === 'sh'?stooges[i].placeCode = '沪': stooges[i].placeCode = '深'
  }
  console.log(stooges,'值修改后数组对象---')

//原数据
dataOld: [{ count: '33', area: '122.2', districtId: 43000 }, { count: '44', area: '168.2', districtId: 43001 }] 
//接口需要的数据
dataNew: [{ countAll: '33', countArea: '122.2', districtId: 43000 }, { count: '44', area: '168.2', districtId: 43001 }]

let dataNew = [];    //新数组
dataOld.map(item => {
    let obj = {
        countAll: item.count,
        countArea: item.area,
        districtId: item.districtId,
    }
     dataNew.push(obj);
});

let dataNew = [];    //新数组
dataOld.map(item => {
    let _item = JSON.parse(JSON.stringify(item).replace('count', 'countAll').replace('area', 'countArea'));
    dataNew.push(_item)
});

convertKey (arr, key) {
    let dataNew = []; //新数组
    this.dataOld.forEach((item, index) => {
        let obj = {}; //新数组里的新对象
        for (var i = 0; i < key.length; i++) {
            obj[key[i]] = item[Object.keys(item)[i]]; //key值替换  
        }
        dataNew.push(obj);
    })
    console.log(dataNew,'dataNew');
    return dataNew;
},
                                            // 改变后的key
let dataNew = this.convertKey(this.dataOld, ['countAll', 'countArea', 'districtId']);