Given two strings s and t , write a function to determine if t is an anagram of s.

    Example 1:

    1. Input: s = "anagram", t = "nagaram"
    2. Output: true

    Example 2:

    Input: s = "rat", t = "car"
Output: false

    Note:
    You may assume the string contains only lowercase alphabets.

    Follow up:
    What if the inputs contain unicode characters? How would you adapt your solution to such case?

    /**
 * @param {string} s
 * @param {string} t
 * @return {boolean}
 */
var isAnagram = function(s, t) {
    const wordMap = new Map();
    let key;
    let value;
    for (let i = 0; i < s.length; i++) {
        key = s[i];
        value = wordMap.get(key);
        if (typeof value === 'undefined') {
            value = 1;
        } else {
            value += 1;
        }
        wordMap.set(key, value);
    }
    for (let i = 0; i < t.length; i++) {
        key = t[i];
        value = wordMap.get(key);
        if (typeof value === 'undefined') {
            return false;
        } else {
            value -= 1;
        }
        wordMap.set(key, value);
    }
    for (let x of wordMap) {
        if (x[1] !== 0) {
            return false;
        }
    }
    return true;
};