numericLiteralParsing

Reports parseInt calls with binary, hexadecimal, or octal strings that can be replaced with numeric literals.

✅ This rule is included in the ts stylistic and stylisticStrict presets.

Binary, octal, and hexadecimal numeric literals provide a more readable and direct way to represent numbers in those bases compared to using parseInt() or Number.parseInt() with a radix argument. Instead of parsing a string representation at runtime, you can use the native literal syntax (0b for binary, 0o for octal, 0x for hexadecimal) which is clearer and more performant.

const 
const binary: number
binary = 
function parseInt(string: string, radix?: number): number
Converts a string to an integer.
@param ― string A string to convert into a number.
@param ― radix A value between 2 and 36 that specifies the base of the number in string.
If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.
All other strings are considered decimal.
parseInt("111110111", 2);

const 
const octal: number
octal = 
function parseInt(string: string, radix?: number): number
Converts a string to an integer.
@param ― string A string to convert into a number.
@param ― radix A value between 2 and 36 that specifies the base of the number in string.
If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.
All other strings are considered decimal.
parseInt("767", 8);

const 
const hex: number
hex = 
function parseInt(string: string, radix?: number): number
Converts a string to an integer.
@param ― string A string to convert into a number.
@param ― radix A value between 2 and 36 that specifies the base of the number in string.
If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.
All other strings are considered decimal.
parseInt("1F7", 16);

const 
const value: number
value = 
var Number: NumberConstructor
An object that represents a number of any kind. All JavaScript numbers are 64-bit floating-point numbers.
Number.
NumberConstructor.parseInt(string: string, radix?: number): number
Converts A string to an integer.
@param ― string A string to convert into a number.
@param ― radix A value between 2 and 36 that specifies the base of the number in string.
If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.
All other strings are considered decimal.
parseInt("FF", 16);

const 
const binary: 503
binary = 0b111110111;

const 
const octal: 503
octal = 0o767;

const 
const hex: 503
hex = 0x1f7;

const 
const value: 255
value = 0xff;

Options

This rule is not configurable.

When Not To Use It

If your project heavily deals with literals and you want to be consistent with their parsing, this rule might not be useful for you.

Equivalents in Other Linters

Biome: useNumericLiterals
ESLint: prefer-numeric-literals
Oxlint: eslint/prefer-numeric-literals

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numericLiteralParsing

Examples

Options

When Not To Use It

Further Reading

Equivalents in Other Linters