Number Utils

Number Utils provides helpers for parsing numbers from strings. Use it when you receive numeric values as strings (e.g. from form inputs or query params) and need a number or undefined for validation or calculations.

Import

import { parseNumber } from '@js-smart/react-kit';

Basic usage

parseNumber('42');      // 42
parseNumber('0');      // 0
parseNumber('');       // undefined
parseNumber(null);     // undefined
parseNumber(undefined); // undefined

With form data or query params

const page = parseNumber(searchParams.get('page')) ?? 1;
const quantity = parseNumber(formData.get('quantity'));
if (quantity !== undefined) {
  // use quantity
}

Notes

• Uses Number.parseInt(value, 10) for base-10 parsing. Non-numeric strings (e.g. "abc") yield NaN; the function returns the result of parseInt, so invalid strings can produce NaN. Check the return value if you need strict validation.
• Returns undefined when the input is not a string (null or undefined).

API Reference

parseNumber

Parses a string to an integer (base 10). Returns undefined if the value is not a string.

Parameter	Type	Description
value	string | null | undefined	Value to parse.

Returns: number | undefined — Parsed integer, or undefined when input is not a string.