根据键值，合并两个数组

原文链接：https://www.thinbug.com/q/46849286

通过es6的map

const arr1 = [
  { id: "abdc4051", date: "2017-01-24" }, 
  { id: "abdc4052", date: "2017-01-22" },
  { id: "abdc4053", date: "2017-01-22" }
];
const arr2 = [
  { nameId: "abdc4051", name: "ab" },
  { nameId: "abdc4052", name: "abc" }
];

const map = new Map();
arr1.forEach(item => map.set(item.id, item));
arr2.forEach(item => map.set(item.nameId, {...map.get(item.nameId), ...item}));
const mergedArr = Array.from(map.values());

通过find 一步到位

let arr1 = [
    { id: "abdc4051", date: "2017-01-24" },
    { id: "abdc4052", date: "2017-01-22" }
];

let arr2 = [
    { id: "abdc4051", name: "ab" },
    { id: "abdc4052", name: "abc" }
];

const mergeById = (a1, a2) =>
    a1.map(itm => ({
        ...a2.find((item) => (item.id === itm.id) && item),
        ...itm
    }));

console.log(mergeById(arr1, arr2));