random-int-array

Returns an array of random integers, with the option of having them be unique.

Node.js Installation

$ npm install random-int-array

Or, simply include random-int-array.js in your web app.

Usage

var randomIntArray = require('random-int-array');

var myRandomIntArray = randomIntArray(options);

options is an object that should contain the following members:

• count - the number of integers in the array
• min - the inclusive lower bound for each random integer (defaults to 0 if not supplied)
• max - the exclusive upper bound for each random integer
• unique - set to true to ensure that all integers in the array are unique - count will shrink to the min and max range if it is greater (defaults to false if not supplied)

Examples

var randomIntArray = require('random-int-array');

randomIntArray({ count: 10, max: 100 });
// Returns an array of 10 integers between 0 and 99

randomIntArray({ count: 3, min: 3, max: 11 });
// Returns an array of 3 integers between 3 and 10.

randomIntArray({ count: 10, max: 101, unique: true });
// Returns an array of 10 integers between 0 and 100, with no duplicates.

Performance Note

When uniqueness is required, one of two different algorithms is selected. Each algorithm performs badly depending on the values supplied for count and the range between min and max. After a bit of testing, I found that I should switch functions when the count is about 16% of the max-min range, so that the best-performing algorithm is used.