1.循环这个数组变成数组对象
var data = [ "USA", "Denmark", "London"];
 var data = [ { "id" : 1, "label": "USA" }, { "id" : 2, "label": "Denmark" }, { "id" : 3, "label": "London" } ];

解决方法：
1.使用push（）

数据阵列 var data = [ "USA", "Denmark", "London"]; 
var demArray =[]; 
data.forEach(function(item,index){ 
demArray.push(
     { id:index+1,label:item }
 )
 }) 
 console.log(demArray)

2.使用map()

var data = [ "USA", "Denmark", "London"]; 
var demArray =[]; 
var demArray = data.map(item => {
  return {
    id:index+1,
    imgurl: item
  }
})
 console.log(demArray)

 // 数组对象相加
    var list = [
      { name: "苹果", count: 20 },
      { name: "橘子", count: 20 },
      { name: "橙子", count: 20 }
    ];

    let countTime = list.reduce((tutu, item) => {
      return tutu + item.count;
    }, 0);
    console.log(countTime, "合并相加");

过滤两个数组并取出不同/相同项（vue/filter）
// 数组A
let arrA = ['1111','2222','333','4444','5555']
// 数组B
   let arrB = [
        { id: "aaa" },
        { id: "bbb" },
        { id: "4444" },
        { id: "5555" },
        { id: "dddd" },
        { id: "eeee" },
        { id: "ffff" },
        { id: "yyyy" },
        { id: "mmmm" }
      ];过滤B数组中不包含A数组的项
let differentArr = arrB.filter(item => arrA.indexOf(item.id) > -1)
// differentArr =['aaa','bbb','dddd','eeee','ffff','yyyy','mmmm']
过滤B数组中包含A数组的项
let differentArr = arrB.filter(item => arrA.indexOf(item.id) != -1)
// differentArr =['4444','5555']