Generate random or sequential UUID of any length.

Use as module

// Deno (web module) Import
import ShortUniqueId from 'https://cdn.jsdelivr.net/npm/short-unique-id@latest/src/index.ts';

// ES6 / TypeScript Import
import ShortUniqueId from 'short-unique-id';

// or Node.js require
const ShortUniqueId = require('short-unique-id');

// Instantiate
const uid = new ShortUniqueId();

// Random UUID
console.log(uid.rnd());

// Sequential UUID
console.log(uid.seq());

Use in browser

<!-- Import -->
<script src="https://cdn.jsdelivr.net/npm/short-unique-id@latest/dist/short-unique-id.min.js"></script>

<!-- Usage -->
<script>
// Instantiate
var uid = new ShortUniqueId();

// Random UUID
document.write(uid.rnd());

// Sequential UUID
document.write(uid.seq());
</script>

Options

Options can be passed when instantiating uid:

const options = { ... };

const uid = new ShortUniqueId(options);

For more information take a look at the ShortUniqueIdOptions type definition.

Hierarchy

  • ShortUniqueId

Constructors

Properties

counter: number
debug: boolean
dict: string[]
dictIndex: number = 0
dictLength: number = 0
dictRange: number[] = []
lowerBound: number = 0
upperBound: number = 0
uuidLength: number
version: string

Methods

  • Calculates approximate number of hashes before first collision.

    Given that:

    • H is the total number of possible UUIDs, or in terms of this library, the result of running availableUUIDs()
    • the expected number of values we have to choose before finding the first collision can be expressed as the quantity Q(H)

    Then Q(H) can be approximated as the square root of the product of half of pi times H:

    This function returns Q(H).

    (see Poisson distribution)

    Parameters

    • rounds: number = ...

    Returns number

  • Calculates total number of possible UUIDs.

    Given that:

    • H is the total number of possible UUIDs
    • n is the number of unique characters in the dictionary
    • l is the UUID length

    Then H is defined as n to the power of l:

    This function returns H.

    Parameters

    • uuidLength: number = ...

    Returns number

  • Calculates probability of generating duplicate UUIDs (a collision) in a given number of UUID generation rounds.

    Given that:

    • r is the maximum number of times that randomUUID() will be called, or better said the number of rounds
    • H is the total number of possible UUIDs, or in terms of this library, the result of running availableUUIDs()

    Then the probability of collision p(r; H) can be approximated as the result of dividing the square root of the product of half of pi times r by H:

    This function returns p(r; H).

    (see Poisson distribution)

    (Useful if you are wondering "If I use this lib and expect to perform at most r rounds of UUID generations, what is the probability that I will hit a duplicate UUID?".)

    Parameters

    • rounds: number = ...
    • uuidLength: number = ...

    Returns number

  • Parameters

    • format: string
    • Optional date: Date

    Returns string

  • Generates custom UUID with the provided format string.

    Parameters

    • format: string
    • Optional date: Date

    Returns string

    Alias

    const uid = new ShortUniqueId(); uid.fmt(format: string);

  • Return the version of this module.

    Returns string

  • Extracts the date embeded in a UUID generated using the uid.stamp(finalLength); method.

     const uidWithTimestamp = uid.stamp(32);
    console.log(uidWithTimestamp);
    // GDa608f973aRCHLXQYPTbKDbjDeVsSb3

    console.log(uid.parseStamp(uidWithTimestamp));
    // 2021-05-03T06:24:58.000Z

    Parameters

    • suid: string
    • Optional format: string

    Returns Date

  • Generates UUID by creating each part randomly.

    Parameters

    • uuidLength: number = ...

    Returns string

    Alias

    const uid = new ShortUniqueId(); uid.rnd(uuidLength: number);

  • Parameters

    • uuidLength: number = ...

    Returns string

  • Generates UUID based on internal counter that's incremented after each ID generation.

    Returns string

    Alias

    const uid = new ShortUniqueId(); uid.seq();

  • Set the counter to a specific value.

    Parameters

    • counter: number

    Returns void

  • Generates a UUID with a timestamp that can be extracted using uid.parseStamp(stampString);.

     const uidWithTimestamp = uid.stamp(32);
    console.log(uidWithTimestamp);
    // GDa608f973aRCHLXQYPTbKDbjDeVsSb3

    console.log(uid.parseStamp(uidWithTimestamp));
    // 2021-05-03T06:24:58.000Z

    Parameters

    • finalLength: number
    • Optional date: Date

    Returns string

  • Calculate a "uniqueness" score (from 0 to 1) of UUIDs based on size of dictionary and chosen UUID length.

    Given that:

    • H is the total number of possible UUIDs, or in terms of this library, the result of running availableUUIDs()
    • Q(H) is the approximate number of hashes before first collision, or in terms of this library, the result of running approxMaxBeforeCollision()

    Then uniqueness can be expressed as the additive inverse of the probability of generating a "word" I had previously generated (a duplicate) at any given iteration up to the the total number of possible UUIDs expressed as the quotiend of Q(H) and H:

    (Useful if you need a value to rate the "quality" of the combination of given dictionary and UUID length. The closer to 1, higher the uniqueness and thus better the quality.)

    Parameters

    • rounds: number = ...

    Returns number

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