JavaScript で文字列の文字を再結合する

const str = 'thi!1s is S@me23';

const output = [ 'thisisSme', '123', '! @' ];

const str = 'thi!1s is S@me23';
const regroupString = (str = '') => {
   const res = ['', '', ''];
   const alpha = 'abcdefghijklmnopqrstuvwxyz';
   const numerals = '0123456789';
   for(let i = 0; i < str.length; i++){
      const el = str[i];
      if(alpha.includes(el) || alpha.includes(el.toLowerCase())){
         res[0] += el;
         continue;
      };
      if(numerals.includes(el)){
         res[1] += el;
         continue;
      };
      res[2] += el;
   };
   return res;
};
console.log(regroupString(str));

[ 'thisisSme', '123', '! @' ]