Detect Capital

LeetCode題目: 520. Detect Capital

My solution:

/**
 * @param {string} word
 * @return {boolean}
 */
let detectCapitalUse = word => {
    if(word === word.toUpperCase()) return true;
    else if(word === word.toLowerCase()) return true;
    else if(word === word.slice(0,1).toUpperCase()+word.slice(1).toLowerCase()) return true;
    return false;
};