使用 lodash 压缩两个对象，其中一个是键，另一个是值

Question

I have objects A and B like this:

const A = { a: 'foo', b: 'bar', c: 'baz' };
const B = { a: 'aaa', b: 'bbb', c: 'ccc' };

I need to transform these two into an object with keys from A and values from B:

{ foo: 'aaa', bar: 'bbb', baz: 'ccc' }

How can I do this with lodash?

Answer 1

Convert the objects into pairs of [key, value] , flatten to a single array, then group by the 1st element (the original key), map the groups to an array of pairs, and convert back to an object.

Using lodash/fp:

 const { rest, flow, map, toPairs, flatten, groupBy, head, last, fromPairs } = _ const fn = rest(flow( map(toPairs), // map each object to pairs of [key, value] flatten, // flatten to a single array of pairs groupBy(head), // group the pairs by the key map(map(last)), // create a new pair by taking the last element of each pair in the group fromPairs // convert to an object )) const A = { b: 'bar', c: 'baz', a: 'foo' } const B = { a: 'aaa', b: 'bbb', c: 'ccc' } const result = fn(A, B) console.log(result)

 <script src='https://cdn.jsdelivr.net/g/lodash@4(lodash.min.js+lodash.fp.min.js)'></script>

Using lodash:

 const { rest, flow, map, toPairs, flatten, groupBy, head, last, fromPairs } = _ const fn = rest(flow( objs => map(objs, toPairs), // map each object to pairs of [key, value] flatten, // flatten to a single array of pairs pairs => groupBy(pairs, head), // group the pairs by the key groups => map(groups, group => map(group, last)), // create a new pair by taking the last element of each pair in the group fromPairs // convert to an object )) const A = { b: 'bar', c: 'baz', a: 'foo' } const B = { a: 'aaa', b: 'bbb', c: 'ccc' } const result = fn(A, B) console.log(result)

 <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js" integrity="sha512-WFN04846sdKMIP5LKNphMaWzU7YpMyCU245etK3g/2ARYbPK9Ub18eG+ljU96qKRCWh+quCY7yefSmlkQw1ANQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>