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Format large numbers in several human-readable ways. Designed for incremental games like Swarm Simulator.

See it in action, and a list of all suffixes.

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Several built-in formats to choose from. Let your users pick their favorite in an options menu!

 numberformat.format(1e10)    // or {format: 'standard'}
 // => "10.000 billion"
 numberformat.format(1e10, {format: 'scientific'})
 // => "1.0000e10"
 numberformat.format(1e10, {format: 'engineering'})
 // => "10.000E9"
 numberformat.format(1e10, {format: 'longScale'})
 // => "10.000 milliard"

At 1e249, 'standard' and 'longScale' fall back to scientific notation.

Use formatShort() or format({flavor:'short'}) to easily abbreviate suffixes and sigfigs.

 // => "10.0B"
 numberformat.formatShort(1e10, {format: 'longScale'})
 // => "10.0Md"

Of course, you can override significant figures.

 numberformat.formatShort(1e10, {sigfigs: 7})
 // => "10.00000B"

Use a formatter object instead of numberformat.format() / numberformat.default to set your own default parameters.

 var f = new numberformat.Formatter({format: 'engineering', sigfigs: 2})
 // => "12E9"

If you need numbers bigger than Number.MAX_VALUE (1e308), there's support for decimal.js.

 numberformat.format(new Decimal('1e10000'), {backend: 'decimal.js', format: 'engineering'})
 // => "10e9999"

decimal.js-light, break_infinity.js and other Decimal.js-compatible number objects are supported too. Pass their constructor to your formatter.

 var Decimal = require('decimal.js-light') // or <script src="decimal.js-light">; load it in whatever way works for your app
 numberformat.format(new Decimal('1e10000'), {backend: 'decimal.js', format: 'engineering', Decimal: Decimal})
 // => "10e9999"

 var Decimal = require('break_infinity.js') // or <script src="break_infinity.js">; load it in whatever way works for your app
 numberformat.format(new Decimal('1e10000'), {backend: 'decimal.js', format: 'engineering', Decimal: Decimal})
 // => "10e9999"

numberformat can parse its own output.

 // => 10000
 numberformat.parse('10 thousand')
 // => 10000
 // => 10000
 // => NaN
 numberformat.parse('', {'default': 3})
 // => 3

swarm-numberformat includes no third-party dependencies, and is less than 20k minified.

The suffixes used here are available in JSON format - this might be useful if your program isn't in Javascript, but can read JSON: standard-suffixes, long-scale-suffixes.

Getting started

<script src="//cdn.rawgit.com/erosson/swarm-numberformat/v0.1.0/dist/swarm-numberformat.min.js"></script>


bower install --save swarm-numberformat


npm install --save swarm-numberformat

const numberformat = require('swarm-numberformat')

Full API documentation. Also see the demo and a list of all suffixes.

The suffixes used by standard and longScale formats are based on http://home.kpn.nl/vanadovv/BignumbyN.html

This project started life as number formatting filters for Swarm Simulator.

https://www.npmjs.com/package/written-number has a lot in common with this project. It has better support for internationalization, but its suffixes stop at smaller numbers, and it has no decimal.js support.

Project template: https://github.com/babel/generator-babel-boilerplate


MIT - use this anywhere. I'd like it if you open-sourced any changes you make to this library (send a pull request? Github fork?), but it's not required.