README

pick-random-weighted

Simple, fast and lightweight function to pick a random element from a weighted array.

Install
Usage
Randomness

Install

npm install pick-random-weighted

Usage

const pick = require('pick-random-weighted');

const colors = [
    ['Red', 30],
    ['Green', 20],
    ['Blue', 40]
];

const color = pick(colors);

pick(values)

Returns a value.

values

Type: Array

List of values to pick from.

Each element should be provided in the format [value, weight].

Random number generation

By default, and to keep a small footprint, the library uses Math.random() to generate the random number to pick the value.

If you need you can define a custom function to generate random values, you can create a function that returns fixed values to use on your unit tests or implement a more specialized library like random-js.

Using a custom random generator

By overwriting pick.random you can define your custom function.

Remember the returned value should be a number within the [0,1) range.

const pick = require('pick-random-weighted');

pick.random = function () {
    return 0.3;
};

const colors = [
    ['Red', 30],
    ['Green', 20],
    ['Blue', 40]
];

const color = pick(colors);
// Will always return 'Green'

Usage no npm install needed!