JS ES6 loop array for of, loop json for in

import * as lib from '../util/constants';

var map = {;
var arr = 'userApi, CouponsApi, CoupondetailApi, addressApi, freeGetApi, categoryApi, pageApi, cartApi'.split (', ');

for (var j of arr) {
  for (var k in lib[j]) {
    var t = lib [j] [k];
    if (typeof t == 'object') {
      for (var n in t) {
        map[k + (n.charAt(0).toUpperCase() + n.slice(1))] = t[n];
      }
    } else {
      map[k] = t;
    }
  }
}