What’s a good way to check if two arrays are equal in JavaScript?

General Discussions
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1

I have arrays like these:

var a = [1, 2, 3];

var b = [3, 2, 1];

var c = new Array(1, 2, 3);

Using == doesn’t work for arrays. I want a method that returns true if two arrays have the same elements in the same order. Does jQuery provide such a method, or how can I check if two arrays are equal JavaScript-style?

2

Hey, with my experience, a solid approach for checking if two arrays are equal in JavaScript is to manually compare their lengths and elements. Here’s a simple function for that:

function arraysEqual(arr1, arr2) {
  if (arr1.length !== arr2.length) return false;
  for (let i = 0; i < arr1.length; i++) {
    if (arr1[i] !== arr2[i]) return false;
  }
  return true;
}

This works great if you want an exact, ordered match between arrays. It’s clear and easy to explain when you’re working in teams.

3

Definitely! If you want a quicker solution and the arrays only contain simple data (like numbers or strings), you can use a more compact method with JSON.stringify. Here’s how you can do it:

function arraysEqual(arr1, arr2) {
  return JSON.stringify(arr1) === JSON.stringify(arr2);
}

It’s a good shortcut for prototyping and works fine when you’re just comparing simple arrays. Just keep in mind that it can be slow with large arrays and depends on the order of elements, so it’s not always the most efficient."

4

Totally! If you’re working with more complex arrays that may contain objects or nested structures, the arraysEqual function might not cut it. A solution here would be to use a library like Lodash to handle deep equality checks:

_.isEqual(arr1, arr2);

Lodash does a fantastic job of handling complex structures and avoids the need for custom comparisons. This could be a better fit when you need something more robust for deep equality checks, especially in larger projects.