Interview question about group anagram answer in javascript

groupAnagram.js

// input: ['tea','you', 'eat', 'ate', 'ouy', 'hard']
// output: [
//     ['tea', 'eat', 'ate'],
//     ['you', 'ouy'],
//     ['hard']
// ]

function groupAnagram(arr) {
  // we will put result here
  const output = {};
  
  // normalize word to get the similarity among all word
  const normalizeWord = (word) => word.split('').sort().join('');
  
  // iterate the array input
  arr.forEach((x) => {
    // if key exist in output
    output[normalizedWord(x)]
      // push the value
      ? output[normalizedWord(x)].push(x)
      // else give a new key and value to output
      : (output[normalizedWord(x)] = [x]);
  });

  // finally, get all output values with Object.values() method
  console.log(Object.values(output));
}

// ref: https://medium.com/javascript-in-plain-english/algorithms-101-group-anagrams-in-javascript-b3e3c10d211e