Check if two strings are permutation of each other in JavaScript

function arePermutation(str1, str2) {
    // Get lengths of both strings
    let n1 = str1.length;
    let n2 = str2.length;

    // If length of both strings
    // is not the same, then they 
    // cannot be permutations
    if (n1 !== n2)
        return false;

    // Convert the strings to arrays
    let ch1 = str1.split('');
    let ch2 = str2.split('');

    // Sort both arrays
    ch1.sort();
    ch2.sort();

    // Compare sorted arrays
    for (let i = 0; i < n1; i++)
        if (ch1[i] !== ch2[i])
            return false;

    return true;
}

// Driver Code
let str1 = "test";
let str2 = "teat";
if (arePermutation(str1, str2))
    console.log("Yes");
else
    console.log("No");

let NO_OF_CHARS = 256;

function arePermutation(str1, str2) {
    // Create 2 count arrays 
    // and initialize all values as 0
    let count1 = Array(NO_OF_CHARS).fill(0);
    let count2 = Array(NO_OF_CHARS).fill(0);

    if (str1.length !== str2.length)
        return false;

    for (let i = 0; i < str1.length && i < str2.length; i++) {
        count1[str1[i].charCodeAt(0)]++;
        count2[str2[i].charCodeAt(0)]++;
    }

    // Compare count arrays
    for (let i = 0; i < NO_OF_CHARS; i++) {
        if (count1[i] !== count2[i])
            return false;
    }

    return true;
}

// Driver code
let str1 = "geeks";
let str2 = "geeks";

if (arePermutation(str1, str2))
    console.log("Yes");
else
    console.log("No");

function arePermutations(str1, str2) {
    // Check if the lengths of
    // both strings are the same
    if (str1.length !== str2.length) {
        return false;
    }

    // Create a Map to store character
    const charFrequencyMap = new Map();

    // Fill the Map with characters 
    for (let char of str1) {
        charFrequencyMap.set(char,
        (charFrequencyMap.get(char) || 0) + 1);
    }

    // Iterate through str2
    for (let char of str2) {
        if (!charFrequencyMap.has(char)) {
        // Character not found in str1
            return false;
        }
        charFrequencyMap.set(char, 
        charFrequencyMap.get(char) - 1);
        if (charFrequencyMap.get(char) === 0) {
            charFrequencyMap.delete(char);
        }
    }

    // If the Map is empty
    // all characters in str2 
    //have been matched
    return charFrequencyMap.size === 0;
}

// Test cases
console.log(arePermutations("abc", "cba"));

function arePermutations(str1, str2) {
  if (str1.length !== str2.length) {
    return false;
  }

  let result = 0;
  for (let i = 0; i < str1.length; i++) {
    result ^= str1.charCodeAt(i) ^ str2.charCodeAt(i);
  }

  return result === 0;
}

const string1 = "abc";
const string2 = "bca";
console.log(arePermutations(string1, string2));

const string3 = "abc";
const string4 = "def";
console.log(arePermutations(string3, string4));