no-null

March 27, 2026 · View on GitHub

📝 Disallow the use of the null literal.

💼🚫 This rule is enabled in the ✅ recommended config. This rule is disabled in the ☑️ unopinionated config.

🔧💡 This rule is automatically fixable by the --fix CLI option and manually fixable by editor suggestions.

Disallow the use of the null literal, to encourage using undefined instead. You can learn why in https://github.com/sindresorhus/meta/discussions/7

Examples

// ❌
let foo = null;

// ✅
let foo;

// ❌
if (bar == null) {}

// ✅
if (bar == undefined) {}

// ✅
const foo = Object.create(null);

// ✅
if (foo === null) {}

Options

Type: object

checkStrictEquality

Type: boolean
Default: false

Strict equality(===) and strict inequality(!==) is ignored by default.

/* eslint unicorn/no-null: ["error", {"checkStrictEquality": true}] */
// ❌
if (foo === null) {}

Why