useSimpleNumberKeys

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/complexity/useSimpleNumberKeys`](/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 [**warning**](/reference/diagnostics#warning). ## How to configure ```json title="biome.json" { "linter": { "rules": { "complexity": { "useSimpleNumberKeys": "error" } } } }

## Description
Disallow number literal object member names which are not base 10 or use underscore as separator.

## Examples

### Invalid

```js
({ 0x1: 1 });

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-simple-number-keys">lint/complexity/useSimpleNumberKeys</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Hexadecimal number literal is not allowed here. > 1 │ ({ 0x1: 1 }); │ ^^^ 2 │ ℹ Safe fix: Replace 0x1 with 1 1 │ - ({·0x1:·1·}); 1 │ + ({·1:·1·}); 2 2 │ </code></pre>

({ 11_1.11: "ee" });

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-simple-number-keys">lint/complexity/useSimpleNumberKeys</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Number literal with underscore is not allowed here. > 1 │ ({ 11_1.11: "ee" }); │ ^^^^^^^ 2 │ ℹ Safe fix: Replace 11_1.11 with 111.11 1 │ - ({·11_1.11:·"ee"·}); 1 │ + ({·111.11:·"ee"·}); 2 2 │ </code></pre>

({ 0o1: 1 });

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-simple-number-keys">lint/complexity/useSimpleNumberKeys</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Octal number literal is not allowed here. > 1 │ ({ 0o1: 1 }); │ ^^^ 2 │ ℹ Safe fix: Replace 0o1 with 1 1 │ - ({·0o1:·1·}); 1 │ + ({·1:·1·}); 2 2 │ </code></pre>

({ 1n: 1 });

({ 11_1.11: "ee" });

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-simple-number-keys">lint/complexity/useSimpleNumberKeys</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Number literal with underscore is not allowed here. > 1 │ ({ 11_1.11: "ee" }); │ ^^^^^^^ 2 │ ℹ Safe fix: Replace 11_1.11 with 111.11 1 │ - ({·11_1.11:·"ee"·}); 1 │ + ({·111.11:·"ee"·}); 2 2 │ </code></pre>

Valid

({ 0: "zero" });
({ 122: "integer" });
({ 1.22: "floating point" });
({ 3.1e12: "floating point with e" });

</TabItem> </Tabs>

Valid

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