Pick the specified properties of an object

ObjectPick.js

/**
 * Pick the specified properties of an object
 *
 * @param obj
 * @param {Array<Array<string> | string>} keys
 * @returns {{}}
 */
function pick (obj, keys) {
  return keys.reduce((sum, k) => (Array.isArray(k) ? sum[k[1]] = obj[k[0]] : sum[k] = obj[k], sum), {})
}

/** USAGE */
pick({a: '1', b: '2', c: '3', d: '4'}, ['a', 'c', ['d', 'e']]) // => {a: '1', c: '3', e: '4'}