4 Methods to Determine If the Contents of Two Arrays Are Equal

Given two arrays, how to determine if the content of both arrays is equal without using sorting and without considering the position of elements.

Example:

[1, 2, 3] and [1, 3, 2] // true
[1, 2, 3] and [1, 2, 4] // false

1. Count Elements Frequency

function areArraysContentEqual(arr1, arr2) {
  if (arr1.length !== arr2.length) {
    return false;
  }

  // Create a counter object to record the frequency of each element in the array
  const countMap1 = count(arr1)
  const countMap2 = count(arr2)

  // Count the frequency of elements in the array
  function count(arr = []) {
    const resMap = new Map();
    for (const item of arr) {
      resMap.set(item, (resMap.get(item) || 0) + 1);
    }
    return resMap
  }
  // Check if the counter objects are equal
  for (const [key, count] of countMap1) {
    if (countMap2.get(key) !== count) {
      return false;
    }
  }

  return true;
}

const array1 = ["apple", "banana", "cherry", "banana", 1, '1', '11', 11];
const array2 = ["banana", "apple", "banana", "cherry", '1', 1, '11', 11];

areArraysContentEqual(array1, array2) // true

2. One Object

function areArraysContentEqual3(arr1= [], arr2 = []) {
  if (arr1.length !== arr2.length) {…