couldBePalindromic.js

function couldBePalindromic(word) {
        let letters = word.split('');

        let matches = letters.map(letter => {
            // How many sets of characters are multiples of 2
            return letters.filter((l) => l == letter).length % 2 == 0
        })
        // Filter out the ones that aren't
        .filter((bool) => bool == true)

        // If the word is even they should all be true, otherwise only one should be false
        return matches.length == (word.length % 2 == 0 ? letters.length : letters.length - 1);
}