需求：有两个均是数组对象结构的数组，如下：

//第一个数组对象结构如下：   arr1数组长度大于arr2
arr1=[
  {adCode:"12340",adName:'河南省'},
  {adCode:"12341",adName:'山东省'},
  {adCode:"12342",adName:'广东省'},
  {adCode:"12343",adName:'上海市'},
  {adCode:"12344",adName:'安徽省'},
]

//第二个数组对象结构如下：
arr2=[
  {adCode:'12342',adValue:"98"},
  {adCode:'12340',adValue:"48"},
  {adCode:'12341',adValue:"90"},
]

由上面的数据结构可以看出，若想获得如下数据结构：

arr3=[
  {adName:"河南省",adValue:"48"}
]

则可进行如下操作：

const arr = arr1.map((v)=>{
    const newResult = arr2.find((item)=>v.adCode ===item.adCode);
    return {adName:v.adName,adValue:newResult.adValue}
})

若arr2数组结构如下：

arr2=[
  {adCode:'12342',adValue:"98"},
  {adCode:'12340',adValue:undefined},
  {adCode:'12341',adValue:"90"},
  {adCode:'12344',adValue:"40"},
  {adCode:'12343',adValue:undefined},
]

则操作如下：

const arr = arr1.map((v)=>{
     //adValue值为undefined时,不纳入新数组arr中
    const newResult = arr2.find((item)=>v.adCode ===item.adCode) || {};
    return {adName:v.adName,adValue:newResult.adValue}
})