Algorithm to return most frequently used words

returnMostFrequentlyUsedWords.js

const wordsToExclude = ['and', 'he', 'the', 'to', 'is', 'Jack', 'Jill']
const literatureText = 'Jack and Jill went to the market to buy bread and cheese. Cheese is Jack\'s and Jill\'s favorite food'

const getTokenizedWords = (word) => {
	if (!word || word === '') return []
	return word.split(/\W+/)
}

const getValidTokenizedWords = (words, excludedWords) => {
	if (!words || words.length === 0) return []
	if (!excludedWords || excludedWords.length === 0) return words
	let validWords = [];

	for (const word of words) {
		if (excludedWords.indexOf(word) == -1) {
			validWords.push(word.toLowerCase())
		}
	}
	return validWords;
}

const getMostFrequentlyUsedWords = (words) => {

	const wordCountMap = {};
	let countWordBucket = []; //Use the indices of the array to keep track of the occurrences of words

	for (const word of words) {
		let count = wordCountMap[word]

		//Check if word exists in map. If it does, it has an existing count, so just add 1 to it
		if (count) {
			wordCountMap[word] = count + 1;
		}
		else {
			//If it doesn't exist, this is the first time we are encountering it, so set it to 1
			wordCountMap[word] = 1;
		}

		count = wordCountMap[word]
		if (countWordBucket[count]) {
			countWordBucket[count].push(word)
		}
		else {
			countWordBucket[count] = [word]
		}
	}

	return countWordBucket[countWordBucket.length - 1]; //The words with the highest occurrence will be at the end of the array

}

const returnMostFrequentlyUsedWords = (literatureText, wordsToExclude) => {
	if (!literatureText || literatureText === '') {
		return []
	}

	const tokenizedWords = getTokenizedWords(literatureText);
	const validTokenizedWords = getValidTokenizedWords(tokenizedWords, wordsToExclude)
	return getMostFrequentlyUsedWords(validTokenizedWords);
}

console.log(returnMostFrequentlyUsedWords(literatureText, wordsToExclude))