merge-arrays-alternatingly-from-tail

const flow = require('lodash/fp/flow'); const map = require('lodash/fp/map'); const reduce = require('lodash/fp/reduce'); const flatten = require('lodash/fp/flatten'); const reverse = require('lodash/fp/reverse'); const alphabets = ['a', 'b', 'c', 'd', 'e']; const numbers = [1, 2, 3]; const alphabets2 = ['f']; const numbers2 = [4]; const mergeArraysAlternatingly = (former, latter) => { console.log(`former array : ${former}`); console.log(`latter array : ${latter}`); return flow( map(array => reverse(array)), reduce((result, array) => { map.convert({cap: false})((item, i) => { (result[i] = result[i] || []).push(item); return result[i]; })(array); return result; }, []), flatten, reverse )([latter, former]); } console.log('result : ' + mergeArraysAlternatingly(alphabets, numbers));