https://github.com/phadej/rc4

RC4 random number generator
https://github.com/phadej/rc4

Last synced: 2 months ago
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RC4 random number generator

• Host: GitHub
• URL: https://github.com/phadej/rc4
• Owner: phadej
• License: mit
• Created: 2014-03-24T07:46:06.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2019-11-07T17:31:51.000Z (about 5 years ago)
• Last Synced: 2024-10-11T23:41:25.051Z (3 months ago)
• Language: JavaScript
• Size: 23.4 KB
• Stars: 5
• Watchers: 3
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# rc4

[RC4](http://en.wikipedia.org/wiki/RC4) random number generator

[![Build Status](https://secure.travis-ci.org/phadej/rc4.svg?branch=master)](http://travis-ci.org/phadej/rc4)

[![NPM version](https://badge.fury.io/js/rc4.svg)](http://badge.fury.io/js/rc4)

[![Dependency Status](https://gemnasium.com/phadej/rc4.svg)](https://gemnasium.com/phadej/rc4)

[![Code Climate](https://img.shields.io/codeclimate/github/phadej/rc4.svg)](https://codeclimate.com/github/phadej/rc4)

## Synopsis

```js

var RC4 = require("rc4");

var generator = new RC4("my seed"); // string or array of integers

// without the seed RNG is seeded with random data from Math.random

// byte := integer ∈ [0, 255]

console.log(generator.randomByte());

// float := number ∈ [0, 1)

console.log(generator.randomFloat());

// save & load state

var state = generator.currentState();

console.log(generator.randomFloat()); // 0.14815412228927016

generator.setState(state);

console.log(generator.randomFloat()); // 0.14815412228927016

```

## RC4small

There is also `RC4small` generator, with smaller internal state:

```

var RC4small = require("rc4").RC4small;

var generator = new RC4small("my seed");

var stateString = generator.currentStateString(); // 18 character hexadecimal string

console.log(generator.randomFloat());  // 0.9362740234937519

generator.setStateString(stateString);

console.log(generator.randomFloat()); // 0.9362740234937519

```

## API

Both `RC4` and `RC4small` have following random value generating methods:

```

randomByte   : () ⇒ { x : ℕ | x ∈ [0, 255] }

randomUInt32 : () ⇒ { x : ℕ | x ∈ [0, 2^32-1] }

randomFloat  : () ⇒ { x : R | x ∈ [0, 1) }

random       : (a : ℤ)        ⇒ { x : ℤ | x ∈ [0, a] }

random       : (a : ℤ, b : ℤ) ⇒ { x : ℤ | x ∈ [a, b] }

```

## Changelog

- **0.1.5** — *2015-04-24* — Better isInteger, random works with bigger ranges

- **0.1.4** — *2015-02-25* — Dev dependencies update