function areAnagrams(wordA, wordB) {
    return areLetterDictsEqual(getWordLetters(wordA), getWordLetters(wordB));
}

function getWordLetters(word) {
    var letters = {};
    word.split('').forEach(letter => {
        letters[letter] = letters[letter] ? (letters[letter] + 1) : 1;
    });
    return letters;
}

function areLetterDictsEqual(lettersA, lettersB) {
    for (var letter in lettersA) {
        if (lettersB[letter] !== lettersA[letter]) {
            return false;
        }
        delete lettersB[letter];
    }
    if (Object.keys(lettersB).length) {
        return false;
    }
    return true;
}