How to compare two arrays in Javascript

Tiziano Cappai — Tue, 18 Apr 2023 07:42:59 +0000

How many times have you found yourself having to verify if the contents of two arrays were equal? (It happens to me often)

Now I’ll show you two ways to solve this problem:

First approach: using JSON.stringify(), see more here

// `a` and `b` are arrays
const isEqual = (a, b) => JSON.stringify(a) === JSON.stringify(b);

// Examples
isEqual([1, 2, 3], [1, 2, 3]); // true
isEqual([1, 2, 3], [1, '2', 3]); // false

Second approach using every(), see more here

// `a` and `b` are arrays
const isEqual = (a, b) => a.length === b.length && a.every((v, i) => v === b[i]);
// Examples
isEqual([1, 2, 3], [1, 2, 3]); // true
isEqual([1, 2, 3], [1, '2', 3]); // false

That's all, hope you re enjoining it! 🙂

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How to compare two arrays in Javascript