---
title: "isEqual"
description: "Deep structural equality check for primitives, arrays, plain objects and Dates."
package: "@maz-ui/utils"
url: "https://maz-ui.com/ecosystem/utils/is-equal"
---

# isEqual

> Deep structural equality check for primitives, arrays, plain objects and Dates.

- Package: `@maz-ui/utils`
- Import: `import { isEqual } from '@maz-ui/utils/helpers/isEqual'`
- Web: https://maz-ui.com/ecosystem/utils/is-equal

## Usage

```ts
import { isEqual } from '@maz-ui/utils'

isEqual({ a: 1, b: [2, 3] }, { a: 1, b: [2, 3] }) // true
isEqual([1, 2, 3], [1, 2, 3]) // true
isEqual(new Date('2024-01-01'), new Date('2024-01-01')) // true
isEqual({ a: 1 }, { a: 1, b: 2 }) // false
```

## API

```ts
function isEqual(a: unknown, b: unknown): boolean
```

| Parameter | Type      | Description       |
| --------- | --------- | ----------------- |
| `a`       | `unknown` | First value       |
| `b`       | `unknown` | Second value      |

## Behaviour

- **Primitives** (`null`, `undefined`, `string`, `number`, `boolean`, `symbol`, `bigint`) - compared with `===`.
- **Dates** - compared by `getTime()`.
- **Arrays** - same length and every element deeply equal.
- **Plain objects** - same set of keys and every value deeply equal.
- **Anything else** (Maps, Sets, class instances, functions) is not specifically handled; comparisons fall back to `===`.