useParseIntRadix

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

<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v2.0.0` - Diagnostic Category: [`lint/correctness/useParseIntRadix`](/reference/diagnostics#diagnostic-category) - This rule is **recommended**, meaning it is enabled by default. - This rule has an [**unsafe**](/linter/#unsafe-fixes) fix. - The default severity of this rule is [**information**](/reference/diagnostics#information). - Sources: - Same as [`radix`](https://eslint.org/docs/latest/rules/radix)

How to configure

json

{
	"linter": {
		"rules": {
			"correctness": {
				"useParseIntRadix": "error"
			}
		}
	}
}

Description

Enforce the consistent use of the radix argument when using parseInt().

When using the parseInt() function it is common to omit the second argument, the radix, and let the function try to determine from the first argument what type of number it is. By default, parseInt() will autodetect decimal and hexadecimal (via 0x prefix). Prior to ECMAScript 5, parseInt() also autodetected octal literals, which caused problems because many developers assumed a leading 0 would be ignored.

This confusion led to the suggestion that you always use the radix parameter to parseInt() to eliminate unintended consequences.

Examples

Invalid

parseInt("071");

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-parse-int-radix">lint/correctness/useParseIntRadix</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Missing radix parameter > 1 │ parseInt("071"); │ ^^^^^^^^^^^^^^^ 2 │ ℹ Add a non-fractional number between 2 and 36 ℹ Unsafe fix: Add a radix of 10 1 │ parseInt("071",·10); │ ++++ </code></pre>

parseInt(someValue);

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-parse-int-radix">lint/correctness/useParseIntRadix</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Missing radix parameter > 1 │ parseInt(someValue); │ ^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Add a non-fractional number between 2 and 36 ℹ Unsafe fix: Add a radix of 10 1 │ parseInt(someValue,·10); │ ++++ </code></pre>

parseInt("071", "abc");

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-parse-int-radix">lint/correctness/useParseIntRadix</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Invalid radix parameter > 1 │ parseInt("071", "abc"); │ ^^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Radix must be a non-fractional number between 2 and 36 </code></pre>

parseInt("071", 37);

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-parse-int-radix">lint/correctness/useParseIntRadix</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Invalid radix parameter > 1 │ parseInt("071", 37); │ ^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Radix must be a non-fractional number between 2 and 36 </code></pre>

parseInt();

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-parse-int-radix">lint/correctness/useParseIntRadix</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ This call to parseInt has no arguments, it will always return NaN > 1 │ parseInt(); │ ^^^^^^^^^^ 2 │ ℹ Add arguments to this function call </code></pre>

Valid

parseInt("071", 10);
parseInt("071", 8);
parseFloat(someValue);

</TabItem> </Tabs>

How to configure

Description

Examples

Invalid

Valid

Related links