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useExponentiationOperator

src/content/docs/linter/rules/use-exponentiation-operator.mdx

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import { Tabs, TabItem } from '@astrojs/starlight/components';

<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v1.0.0` - Diagnostic Category: [`lint/style/useExponentiationOperator`](/reference/diagnostics#diagnostic-category) - This rule is **recommended**, meaning it is enabled by default. - This rule has a [**safe**](/linter/#safe-fixes) fix. - The default severity of this rule is [**information**](/reference/diagnostics#information). - Sources: - Same as [`prefer-exponentiation-operator`](https://eslint.org/docs/latest/rules/prefer-exponentiation-operator) - Same as [`e18e/prefer-exponentiation-operator`](https://github.com/e18e/eslint-plugin)

How to configure

json
{
	"linter": {
		"rules": {
			"style": {
				"useExponentiationOperator": "error"
			}
		}
	}
}

Description

Disallow the use of Math.pow in favor of the ** operator.

Introduced in ES2016, the infix exponentiation operator ** is an alternative for the standard Math.pow function. Infix notation is considered to be more readable and thus more preferable than the function notation.

Examples

Invalid

js
const foo = Math.pow(2, 8);
<pre class="language-text"><code class="language-text">code-block.js:1:13 <a href="https://biomejs.dev/linter/rules/use-exponentiation-operator">lint/style/useExponentiationOperator</a> <span style="color: #000; background-color: #ddd;"> FIXABLE </span> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>const foo = Math.pow(2, 8); <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Safe fix</span><span style="color: lightgreen;">: </span><span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong>1</strong> <strong> │ </strong><span style="color: Tomato;">-</span> <span style="color: Tomato;">c</span><span style="color: Tomato;">o</span><span style="color: Tomato;">n</span><span style="color: Tomato;">s</span><span style="color: Tomato;">t</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">f</span><span style="color: Tomato;">o</span><span style="color: Tomato;">o</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">=</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;"><strong>M</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>t</strong></span><span style="color: Tomato;"><strong>h</strong></span><span style="color: Tomato;"><strong>.</strong></span><span style="color: Tomato;"><strong>p</strong></span><span style="color: Tomato;"><strong>o</strong></span><span style="color: Tomato;"><strong>w</strong></span><span style="color: Tomato;"><strong>(</strong></span><span style="color: Tomato;">2</span><span style="color: Tomato;"><strong>,</strong></span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">8</span><span style="color: Tomato;"><strong>)</strong></span><span style="color: Tomato;">;</span> <strong>1</strong><strong> │ </strong><span style="color: MediumSeaGreen;">+</span> <span style="color: MediumSeaGreen;">c</span><span style="color: MediumSeaGreen;">o</span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">s</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">f</span><span style="color: MediumSeaGreen;">o</span><span style="color: MediumSeaGreen;">o</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">=</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">2</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;"><strong>·</strong></span></span><span style="color: MediumSeaGreen;">8</span><span style="color: MediumSeaGreen;">;</span> <strong>2</strong> <strong>2</strong><strong> │ </strong> </code></pre>
js
const bar = Math.pow(a, b);
<pre class="language-text"><code class="language-text">code-block.js:1:13 <a href="https://biomejs.dev/linter/rules/use-exponentiation-operator">lint/style/useExponentiationOperator</a> <span style="color: #000; background-color: #ddd;"> FIXABLE </span> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>const bar = Math.pow(a, b); <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Safe fix</span><span style="color: lightgreen;">: </span><span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong>1</strong> <strong> │ </strong><span style="color: Tomato;">-</span> <span style="color: Tomato;">c</span><span style="color: Tomato;">o</span><span style="color: Tomato;">n</span><span style="color: Tomato;">s</span><span style="color: Tomato;">t</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">b</span><span style="color: Tomato;">a</span><span style="color: Tomato;">r</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">=</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;"><strong>M</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>t</strong></span><span style="color: Tomato;"><strong>h</strong></span><span style="color: Tomato;"><strong>.</strong></span><span style="color: Tomato;"><strong>p</strong></span><span style="color: Tomato;"><strong>o</strong></span><span style="color: Tomato;"><strong>w</strong></span><span style="color: Tomato;"><strong>(</strong></span><span style="color: Tomato;">a</span><span style="color: Tomato;"><strong>,</strong></span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">b</span><span style="color: Tomato;"><strong>)</strong></span><span style="color: Tomato;">;</span> <strong>1</strong><strong> │ </strong><span style="color: MediumSeaGreen;">+</span> <span style="color: MediumSeaGreen;">c</span><span style="color: MediumSeaGreen;">o</span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">s</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">b</span><span style="color: MediumSeaGreen;">a</span><span style="color: MediumSeaGreen;">r</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">=</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">a</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;"><strong>·</strong></span></span><span style="color: MediumSeaGreen;">b</span><span style="color: MediumSeaGreen;">;</span> <strong>2</strong> <strong>2</strong><strong> │ </strong> </code></pre>
js
let baz = Math.pow(a + b, c + d);
<pre class="language-text"><code class="language-text">code-block.js:1:11 <a href="https://biomejs.dev/linter/rules/use-exponentiation-operator">lint/style/useExponentiationOperator</a> <span style="color: #000; background-color: #ddd;"> FIXABLE </span> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>let baz = Math.pow(a + b, c + d); <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Safe fix</span><span style="color: lightgreen;">: </span><span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong>1</strong> <strong> │ </strong><span style="color: Tomato;">-</span> <span style="color: Tomato;">l</span><span style="color: Tomato;">e</span><span style="color: Tomato;">t</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">b</span><span style="color: Tomato;">a</span><span style="color: Tomato;">z</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">=</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;"><strong>M</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>t</strong></span><span style="color: Tomato;"><strong>h</strong></span><span style="color: Tomato;"><strong>.</strong></span><span style="color: Tomato;"><strong>p</strong></span><span style="color: Tomato;"><strong>o</strong></span><span style="color: Tomato;"><strong>w</strong></span><span style="color: Tomato;">(</span><span style="color: Tomato;">a</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">+</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">b</span><span style="color: Tomato;"><strong>,</strong></span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">c</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">+</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">d</span><span style="color: Tomato;">)</span><span style="color: Tomato;">;</span> <strong>1</strong><strong> │ </strong><span style="color: MediumSeaGreen;">+</span> <span style="color: MediumSeaGreen;">l</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">b</span><span style="color: MediumSeaGreen;">a</span><span style="color: MediumSeaGreen;">z</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">=</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">(</span><span style="color: MediumSeaGreen;">a</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">+</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">b</span><span style="color: MediumSeaGreen;"><strong>)</strong></span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;"><strong>·</strong></span></span><span style="color: MediumSeaGreen;"><strong>(</strong></span><span style="color: MediumSeaGreen;">c</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">+</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">d</span><span style="color: MediumSeaGreen;">)</span><span style="color: MediumSeaGreen;">;</span> <strong>2</strong> <strong>2</strong><strong> │ </strong> </code></pre>
js
let quux = Math.pow(-1, n);
<pre class="language-text"><code class="language-text">code-block.js:1:12 <a href="https://biomejs.dev/linter/rules/use-exponentiation-operator">lint/style/useExponentiationOperator</a> <span style="color: #000; background-color: #ddd;"> FIXABLE </span> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>let quux = Math.pow(-1, n); <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Safe fix</span><span style="color: lightgreen;">: </span><span style="color: lightgreen;">Use the '&#42;&#42;' operator instead of 'Math.pow'.</span> <strong>1</strong> <strong> │ </strong><span style="color: Tomato;">-</span> <span style="color: Tomato;">l</span><span style="color: Tomato;">e</span><span style="color: Tomato;">t</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">q</span><span style="color: Tomato;">u</span><span style="color: Tomato;">u</span><span style="color: Tomato;">x</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">=</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;"><strong>M</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>t</strong></span><span style="color: Tomato;"><strong>h</strong></span><span style="color: Tomato;"><strong>.</strong></span><span style="color: Tomato;"><strong>p</strong></span><span style="color: Tomato;"><strong>o</strong></span><span style="color: Tomato;"><strong>w</strong></span><span style="color: Tomato;">(</span><span style="color: Tomato;">-</span><span style="color: Tomato;">1</span><span style="color: Tomato;"><strong>,</strong></span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">n</span><span style="color: Tomato;"><strong>)</strong></span><span style="color: Tomato;">;</span> <strong>1</strong><strong> │ </strong><span style="color: MediumSeaGreen;">+</span> <span style="color: MediumSeaGreen;">l</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">q</span><span style="color: MediumSeaGreen;">u</span><span style="color: MediumSeaGreen;">u</span><span style="color: MediumSeaGreen;">x</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">=</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">(</span><span style="color: MediumSeaGreen;">-</span><span style="color: MediumSeaGreen;">1</span><span style="color: MediumSeaGreen;"><strong>)</strong></span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><strong>&#42;</strong></span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;"><strong>·</strong></span></span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">;</span> <strong>2</strong> <strong>2</strong><strong> │ </strong> </code></pre>

Valid

js
const foo = 2 ** 8;

const bar = a ** b;

let baz = (a + b) ** (c + d);

let quux = (-1) ** n;
</TabItem> </Tabs>