我有两个集合,并且对象有一个公用键“userId”。如下:
var _= require('lodash');
var a = [
{ userId:"p1", item:1},
{ userId:"p2", item:2},
{ userId:"p3", item:4}
];
var b = [
{ userId:"p1", profile:1},
{ userId:"p2", profile:2}
];
我想基于“userId”合并它们以产生:
[ { userId: 'p1', item: 1, profile: 1 },
{ userId: 'p2', item: 2, profile:2 },
{ userId: 'p3', item: 4 } ]
到目前为止,我有这些:
var u = _.uniq(_.union(a, b), false, _.property('userId'));
结果是:
[ { userId: 'p1', item: 1 },
{ userId: 'p2', item: 2 },
{ userId: 'p3', item: 4 },
{ userId: 'p1', profile: 1 },
{ userId: 'p2', profile: 2 } ]
我现在如何合并它们?
我尝试了_.keyBy,但结果是:
{ p1: { userId: 'p1', profile: 1 },
p2: { userId: 'p2', profile: 2 },
p3: { userId: 'p3', item: 4 } }
这是错误的。
我应该做的最后一步是什么?
最佳答案
投票率最高的答案无法正确合并。如果第二个数组包含唯一属性,则不考虑它。
这种方法可以进行正确的合并。
Lodash
var a = [
{ userId:"p1", item:1},
{ userId:"p2", item:2},
{ userId:"p3", item:4}
];
var b = [
{ userId:"p1", profile:1},
{ userId:"p2", profile:2},
{ userId:"p4", profile:4}
];
var merged = _.merge(_.keyBy(a, 'userId'), _.keyBy(b, 'userId'));
var values = _.values(merged);
console.log(values);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>
ES6 +
// from https://stackoverflow.com/a/34749873/80766
const mergeDeep = (target, ...sources) => {
if (!sources.length) return target;
const source = sources.shift();
if (target instanceof Object && source instanceof Object) {
for (const key in source) {
if (source[key] instanceof Object) {
if (!target[key]) Object.assign(target, { [key]: {} });
mergeDeep(target[key], source[key]);
} else {
Object.assign(target, { [key]: source[key] });
}
}
}
return mergeDeep(target, ...sources);
}
const a = [
{ userId:"p1", item:1},
{ userId:"p2", item:2},
{ userId:"p3", item:4}
];
const b = [
{ userId:"p1", profile:1},
{ userId:"p2", profile:2},
{ userId:"p4", profile:4}
];
const aKeyed = a.reduce((acc, cur) => ({ ...acc, [cur.userId]: cur }), {});
const bKeyed = b.reduce((acc, cur) => ({ ...acc, [cur.userId]: cur }), {});
const merged = mergeDeep(aKeyed, bKeyed);
const values = Object.values(merged);
console.log(values);