ThinkFul(read code)

mostFrequentWord

function getTokens(rawString) {

// Returns array of strings, with lower case,  spaces and ,!.";:- - these simbols will be deleted 
//regardless of how many times they were repeated and will be removed any falsy items from an array
// the array will be sorted alphabetically. As a result, an array of words is returned in the alphabetical order.
  return rawString.toLowerCase().split(/[ ,!.";:-]+/).filter(Boolean).sort();
}

function mostFrequentWord(text) {

// For the text fragment "text" we form a word array in alphabetical order and save it in the "words" array
  let words = getTokens(text);

//create an object for counting the number of words
  let wordFrequencies = {};

// It is going to iterate thru the array "words", from index 0 till last index of array
// In the condition, it is checked whether there is a current word in wordFrequencies, 
//if there is, then the counter is updated for this words to + 1, and if not, 
//then this word with the initial value 1 is added.
  for (let i = 0; i <= words.length; i++) {
    if (words[i] in wordFrequencies) {
      wordFrequencies[words[i]]++;
    } else {
      wordFrequencies[words[i]] = 1;
    }
  }

// In the wordFrequencies object, the key with index 0 has the current maximum number of matches,
// This value is saved in variable currentMaxCount  
  let currentMaxKey = Object.keys(wordFrequencies)[0];
  let currentMaxCount = wordFrequencies[currentMaxKey];

// It is going to iterate thru all the keys of the wordFrequencies object and check that there are words with 
//a value greater than our current maximum, if there is then change our current maximum to a new value 
  for (let word in wordFrequencies) {
    if (wordFrequencies[word] > currentMaxCount) {
      currentMaxKey = word;
      currentMaxCount = wordFrequencies[word];
    }
  }
  
// return the word with the maximum number of matches
  return currentMaxKey;
}