isNil (Lodash Compatibility)

::: warning Use es-toolkit's isNil instead

This isNil function operates slowly due to complex handling for Lodash compatibility.

Use the faster and more modern es-toolkit's isNil instead.

:::

Checks if a value is null or undefined.

const result = isNil(value);

Usage

isNil(x)

Use isNil when you want to type-safely check if a value is null or undefined. It also works as a type guard in TypeScript.

import { isNil } from 'es-toolkit/compat';

// null and undefined return true
isNil(null); // true
isNil(undefined); // true

// All other values return false
isNil(0); // false
isNil(''); // false
isNil(false); // false
isNil([]); // false
isNil({}); // false
isNil('hello'); // false
isNil(42); // false

It distinguishes from values that are truthy but not null or undefined.

import { isNil } from 'es-toolkit/compat';

// Values that are falsy but not null/undefined
isNil(0); // false
isNil(''); // false
isNil(false); // false
isNil(NaN); // false

// Only null and undefined return true
isNil(null); // true
isNil(undefined); // true

Parameters

• x (any): The value to check if it's null or undefined.

Returns

(x is null | undefined): Returns true if the value is null or undefined, false otherwise.