wNumb: JavaScript Number & Money Formatting

1.2.0 · maintenance · verified Sun Apr 19

wNumb is a lightweight JavaScript utility designed specifically for number and money formatting. It enables developers to control aspects such as decimal places, thousands separators, and the addition of prefixes or suffixes to numerical values, facilitating clear and readable data presentation. The current stable version is 1.2.0, released in October 2019. The project appears to have an irregular release cadence, with no updates since 2019, suggesting it is currently in a maintenance phase rather than active development. Its core value lies in offering a focused, minimal API for common formatting needs, differentiating itself from more comprehensive internationalization libraries by prioritizing simplicity and a small footprint.

Common errors

```
Formatter outputs '-0' for negative numbers with `decimals: 0`
```
cause You are using an older version of wNumb (prior to 1.0.2) which had a bug in rounding very small negative numbers.

fix Upgrade your wNumb package to version 1.0.2 or higher.
```
Unexpected behavior or incorrect parsing when handling decimal values.
```
cause Your wNumb version is older than 1.0.1, which contained a bug related to decimal processing.

fix Upgrade your wNumb package to version 1.0.1 or higher.
```
The `postfix` option is ignored or does not apply the desired text.
```
cause In version 1.1.0, the `postfix` option was renamed to `suffix`. While an internal remapping exists, direct use of `suffix` is recommended.

fix Change your formatter configuration from `postfix: 'TEXT'` to `suffix: 'TEXT'`.

Warnings

breaking The `postfix` option was renamed to `suffix` in version 1.1.0. While `postfix` is remapped internally for backward compatibility, relying on the old name is deprecated and may lead to unexpected behavior or removal in future updates.
Fix: Update your formatter configurations to use `suffix` instead of `postfix`.
gotcha When formatting small negative numbers with `decimals` set to 0, older versions (prior to 1.0.2) could display '-0' instead of '0'.
Fix: Upgrade to wNumb version 1.0.2 or newer to resolve this display issue.
gotcha Early versions (prior to 1.0.1) had issues with decimal handling, potentially leading to incorrect formatting or parsing of values with fractional components.
Fix: Upgrade to wNumb version 1.0.1 or newer to ensure correct decimal processing.

Install

npm install wnumb npm
yarn add wnumb yarn
pnpm add wnumb pnpm

Imports

wNumb
wrong:
```
import { wNumb } from 'wnumb';
```
correct:
```
import wNumb from 'wnumb';
```
wNumb is typically consumed as a default export when using modern bundlers or CommonJS environments. It is not a named export.
wNumb (CommonJS)
```
const wNumb = require('wnumb');
```
For Node.js or older environments using CommonJS, wNumb is imported as a module.
wNumb (Global)
```
const formatter = wNumb({...}); // Assumes wNumb script tag is present
```
When included via a <script> tag in a browser, wNumb is exposed globally as the 'wNumb' function.

Quickstart

Demonstrates how to create and use wNumb formatters for currency, percentages, and custom numeric transformations, including encoding and decoding values.

import wNumb from 'wnumb'; // For module environments like Node.js or bundlers
// If using directly in browser via script tag, 'wNumb' is global.

// Create a currency formatter for USD
const usdFormatter = wNumb({
    decimals: 2,           // Number of decimals (e.g., 2 for $XX.XX)
    mark: '.',             // Decimal separator
    thousand: ',',         // Thousands separator
    prefix: '$ ',
    suffix: ' USD'
});

console.log(usdFormatter.to(12345.678));
// Expected output: "$ 12,345.68 USD"

console.log(usdFormatter.from('$ 5,432.10 USD'));
// Expected output: 5432.1

// Create a percentage formatter
const percentFormatter = wNumb({
    decimals: 0,
    suffix: '%'
});

console.log(percentFormatter.to(0.75));
// Expected output: "75%"

console.log(percentFormatter.from('99%'));
// Expected output: 0.99

// A simple number formatter with specific rounding
const numberFormatter = wNumb({
    decimals: 3,
    encoder: value => value * 2, // Example: custom encode function
    decoder: value => value / 2  // Example: custom decode function
});

console.log(numberFormatter.to(10.1234));
// Expected output: "20.247" (10.1234 * 2 = 20.2468, rounded to 3 decimals)

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