useArrayLiterals

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

<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v1.7.2` - Diagnostic Category: [`lint/style/useArrayLiterals`](/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 [`no-array-constructor`](https://eslint.org/docs/latest/rules/no-array-constructor) - Same as [`@typescript-eslint/no-array-constructor`](https://typescript-eslint.io/rules/no-array-constructor)

How to configure

json

{
	"linter": {
		"rules": {
			"style": {
				"useArrayLiterals": "error"
			}
		}
	}
}

Description

Disallow Array constructors.

Use of the Array constructor to construct a new array is generally discouraged in favor of array literal notation because of the single-argument pitfall and because the Array global may be redefined. The exception is when the Array constructor intentionally creates sparse arrays of a specified size by giving the constructor a single numeric argument.

Examples

Invalid

const xs = Array();

const xs = Array(0, 1, 2);

<pre class="language-text"><code class="language-text">code-block.js:1:12 <a href="https://biomejs.dev/linter/rules/use-array-literals">lint/style/useArrayLiterals</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Use an array literal instead of the Array constructor. > 1 │ const xs = Array(0, 1, 2); │ ^^^^^^^^^^^^^^ 2 │ ℹ The Array constructor is misleading because it can be used to preallocate an array of a given length or to create an array with a given list of elements. ℹ Safe fix: Use an array literal. 1 │ - const·xs·=·Array(0,·1,·2); 1 │ + const·xs·=·[0,·1,·2]; 2 2 │ </code></pre>

const xs = new Array(0, 1, 2);

<pre class="language-text"><code class="language-text">code-block.js:1:12 <a href="https://biomejs.dev/linter/rules/use-array-literals">lint/style/useArrayLiterals</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Use an array literal instead of the Array constructor. > 1 │ const xs = new Array(0, 1, 2); │ ^^^^^^^^^^^^^^^^^^ 2 │ ℹ The Array constructor is misleading because it can be used to preallocate an array of a given length or to create an array with a given list of elements. ℹ Safe fix: Use an array literal. 1 │ - const·xs·=·new·Array(0,·1,·2); 1 │ + const·xs·=·[0,·1,·2]; 2 2 │ </code></pre>

const xs = Array(...args);

<pre class="language-text"><code class="language-text">code-block.js:1:12 <a href="https://biomejs.dev/linter/rules/use-array-literals">lint/style/useArrayLiterals</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Use an array literal instead of the Array constructor. > 1 │ const xs = Array(...args); │ ^^^^^^^^^^^^^^ 2 │ ℹ The Array constructor is misleading because it can be used to preallocate an array of a given length or to create an array with a given list of elements. ℹ Safe fix: Use an array literal. 1 │ - const·xs·=·Array(...args); 1 │ + const·xs·=·[...args]; 2 2 │ </code></pre>

const xs = new Array<number>()

<pre class="language-text"><code class="language-text">code-block.ts:1:12 <a href="https://biomejs.dev/linter/rules/use-array-literals">lint/style/useArrayLiterals</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Use an array literal instead of the Array constructor. > 1 │ const xs = new Array<number>() │ ^^^^^^^^^^^^^^^^^^^ 2 │ ℹ The Array constructor is misleading because it can be used to preallocate an array of a given length or to create an array with a given list of elements. ℹ Safe fix: Use an array literal. 1 │ - const·xs·=·new·Array<number>() 1 │ + const·xs:·number[]·=·[] 2 2 │ </code></pre>

Valid

const xs = Array(65000);

const xs = [0, 1, 2];

</TabItem> </Tabs>

How to configure

Description

Examples

Invalid

Valid

Related links