# no-negated-comparison

📝 Disallow negated comparisons.

💼 This rule is enabled in the following [configs](https://github.com/sindresorhus/eslint-plugin-unicorn#recommended-config): ✅ `recommended`, ☑️ `unopinionated`.

🔧💡 This rule is automatically fixable by the [`--fix` CLI option](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix) and manually fixable by [editor suggestions](https://eslint.org/docs/latest/use/core-concepts#rule-suggestions).

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Prefer using the opposite comparison operator instead of negating the whole comparison.

By default, the rule intentionally does not rewrite compound logical expressions like `!(a === b && c === d)`. Keeping the grouped negation can be easier to read.

## Examples

```js
// ❌
const isDifferent = !(a === b);

// ✅
const isDifferent = a !== b;
```

```js
// ❌
if (!(typeof value === 'undefined')) {}

// ✅
if (typeof value !== 'undefined') {}
```

```js
// ✅
if (!(a === b && c === d)) {}
```

## Options

Type: `object`

### checkLogicalExpressions

Type: `boolean`\
Default: `false`

Check logical expressions that only contain comparisons.

This option intentionally does not attempt broad boolean algebra simplification. It ignores logical expressions with non-comparison parts and reports without a fix or suggestion when comments are inside the negated expression.

```js
{
	'unicorn/no-negated-comparison': [
		'error',
		{
			checkLogicalExpressions: true,
		},
	],
}
```

```js
// ❌
if (!(a === b && c === d)) {}

// ✅
if (a !== b || c !== d) {}
```

```js
// ❌
if (!(a === b && (c === d || e === f))) {}

// ✅
if (a !== b || (c !== d && e !== f)) {}
```