coderain

a javascript library to genarate unique random codes

Demo

You can see CodeRain in action here: https://toolity.org/random-codes

Instalation

Browser

Download coderain.js and include it in your HTML file:

<script src="coderain.js"></script>

Node

$ npm install coderain

Usage

First you need to create a new instance of CodeRain specifying a code pattern. In the example we are going to generate codes consisting of 3 random uppercase letters followed by a hyphen and 5 random digits.

var cr = new CodeRain("AAA-99999");

Then you can keep calling next() and it's guaranteed that generated codes are unique, i.e. they don't repeat for given CodeRain instance.

For example to get an array of 1000 unique random codes:

var codes = [];
while (codes.length < 1000) {
    codes.push(cr.next());
}

Patterns

placeholder	possible characters	description
A	ABCDEFGHIJKLMNOPQRSTUVWXYZ	uppercase letters
a	abcdefghijklmnopqrstuvwxyz	lowercase letters
9	0123456789	digits
X	ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789	uppercase letters + digits
x	abcdefghijklmnopqrstuvwxyz0123456789	lowercase letters + digits
#	ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789	uppercase and lowercase letters + digits

If you would like to use reserved characters in you pattern you can quote it with single quotes, for example:

var xmasCodes = new CodeRain("'XMAS'-XXXXX")

Combinations

For every code pattern there is a maximum number of possible combinations. To get this number for your pattern just invoke combinations() on the CodeRain instance.

For example there are 10000 possible 4-digits codes (0000-9999):

var 4digitCodes = new CodeRain("9999");
4digitCodes.combinations(); // returns 10000

License

Code released under the MIT license.