Package Exports
- @alwatr/is-number
Readme
is-number
A lightweight, high-performance utility to check if a value is a number or can be converted to a number.
Installation
yarn add @alwatr/is-number
# or
npm install @alwatr/is-numberUsage
import {isNumber, toNumber, isFiniteNumber} from '@alwatr/is-number';
// Check if a value is a number
isNumber(123); // true
isNumber('123'); // true
isNumber('abc'); // false
// Convert a value to a number if possible
toNumber(123); // 123
toNumber('123'); // 123
toNumber('abc'); // null
// Check if a value is a finite number (without type coercion)
isFiniteNumber(123); // true
isFiniteNumber(Infinity); // false
isFiniteNumber('123'); // false (no coercion)API
isNumber(value: unknown): boolean
Checks if the value is a number or can be converted to a number.
toNumber(value: unknown): number | null
Converts the value to a number if possible, otherwise returns null.
isFiniteNumber(value: unknown): boolean
A cross-browser polyfill for Number.isFinite. Unlike the global isFinite,
this doesn't coerce values to numbers before checking.
Why is this needed?
JavaScript type behavior can be confusing. This library helps to simplify number validation:
console.log(typeof '123'); // 'string'
console.log(+[]); // 0
console.log(+''); // 0
console.log(+' '); // 0
console.log(typeof NaN); // 'number'
console.log(typeof Infinity); // 'number'isNumber Examples
Returns true
isNumber(5e3); // true
isNumber(0xff); // true
isNumber(-1.1); // true
isNumber(0); // true
isNumber(1); // true
isNumber(1.1); // true
isNumber('-1.1'); // true
isNumber('0'); // true
isNumber('0xff'); // true
isNumber('1'); // true
isNumber('1.1'); // true
isNumber('5e3'); // true
isNumber('012'); // true
isNumber(' 123 '); // trueReturns false
isNumber(Infinity); // false
isNumber(NaN); // false
isNumber(null); // false
isNumber(undefined); // false
isNumber(''); // false
isNumber(' '); // false
isNumber('foo'); // false
isNumber('123foo'); // false
isNumber([1]); // false
isNumber([]); // false
isNumber(function () {}); // false
isNumber({}); // falsetoNumber Examples
Returns a number
toNumber(5e3); // 5000
toNumber(0xff); // 255
toNumber(-1.1); // -1.1
toNumber(0); // 0
toNumber(1); // 1
toNumber('-1.1'); // -1.1
toNumber('0'); // 0
toNumber('0xff'); // 255
toNumber('5e3'); // 5000
toNumber(' 123 '); // 123Returns null
toNumber(Infinity); // null
toNumber(NaN); // null
toNumber(null); // null
toNumber(undefined); // null
toNumber(''); // null
toNumber(' '); // null
toNumber('foo'); // null
toNumber('123foo'); // null
toNumber([1]); // null
toNumber([]); // null
toNumber(function () {}); // null
toNumber({}); // nullSponsors
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Contributing
Contributions are welcome! Please read our contribution guidelines before submitting a pull request.