Given two strings, write a function to determine if the second string is an anagram of the first. An anagram is a word, phrase, or name formed by rearranging the letters of another, such as cinema, formed from iceman.

validateAnagram.js

function validAnagram(str1, str2) {
    if (typeof str1 != "string" || typeof str2 != "string") return false;
    if (str1.length != str2.length) return false;
    [str1, str2] = [str1.toLocaleLowerCase(), str2.toLocaleLowerCase()]
    let frequencyStr1 = {}
    let frequencyStr2 = {}
    for (let char of str1) {
        frequencyStr1[char] = (frequencyStr1[char] || 0) + 1
    }
    for (let char of str2) {
        frequencyStr2[char] = (frequencyStr2[char] || 0) + 1
    }
    for (let char in frequencyStr1) {
        if (frequencyStr1[char] != frequencyStr2[char]) {
            return false
        }
    }
    return true

}


validAnagram('', ''), // true
validAnagram('aaz', 'zza'), // false
validAnagram('anagram', 'nagaram'), // true
validAnagram("rat", "car"), // false) // false
validAnagram('awesome', 'awesom'), // false
validAnagram('qwerty', 'qeywrt'), // true
validAnagram('texttwisttime', 'timetwisttext') // true