let basic = "abcdefghijklmnopqrstuvwxyz0123456789".split(""); let keys = "ijklmnopqrstuvwxyz0123456789abcdefgh".split(""); // let translator = basic.map((key, index) => ( { [key]: keys[index]})); // let translator = basic.map((key, index) => ( { [key]: keys[index]})); let translator = basic.reduce((c, e, i) => { c[[e]] = keys[i]; return c; }, {".": ""}); console.log(translator);