/**
 * @param {string[]} strs
 * @return {string[][]}
 */
var groupAnagrams = function (strs) {
  let hash = {};
  for (let i = 0; i < strs.length; i++) {
    let sorted = [...strs[i]].sort().join('');
    hash[sorted] ? hash[sorted].push(strs[i]) : (hash[sorted] = [strs[i]]);
  }
  return Object.values(hash);
};

/**
 * @param {string[]} strs
 * @return {string[][]}
 */
var groupAnagrams = function (strs) {
  let arr = [];
  for (let i = 0; i < strs.length; i++) {
    let sorted = [...strs[i]].sort().join('');
    arr[sorted] = arr[sorted] ? [...arr[sorted], strs[i]] : [strs[i]];
  }
  console.log(arr);
  //   [ aet: [ 'eat', 'tea', 'ate' ], ant: [ 'tan', 'nat' ], abt: [ 'bat' ] ]
  return Object.values(arr);
};

console.log(groupAnagrams(['eat', 'tea', 'tan', 'ate', 'nat', 'bat']));