Generate UUID v4: Understanding the Process and Implementation Details

UUIDs, or universally unique identifiers, are 128-bit numbers used to uniquely identify items in software development. In this version, the UUID is generated by taking the current timestamp and some identifying property of the device generating the UUID – most commonly, the MAC address (also called the node ID). This process is often referred to as Version 1.

Version 1 (Time Based + Unique or Random Host Identifier)

In this variant, the most significant bits of N are fixed at 1 and 0. The interpretation of all other bits in the UUID depends on the value of the variant. The variant field determines the layout of the information embedded in the UUID.

The values in the M and N locations uniquely identify the UUID version and variant respectively. Their canonical textual representation is as a series of 32 hexadecimal characters which are separated into five groups by hyphens in the form 8-4-4-4-12.

Embedded inside this seemingly random series of hexadecimal characters is information about the UUID implementation. The modern-day implementation of UUIDs can be tied back to RFC 4122, which introduced 5 different approaches for generating these identifiers.

In Node.js, you can use V4() to generate a large number which is translated into a hexadecimal string. This means that considering our wildcard values – the bits marked with an x above – the only possible values are 8, 9, A, or B.

The following table lists the currently defined versions:

| Variant | Version Number |

| --- | --- |

| |

We identify the variant by considering the first 1-3 most significant bits of N. The interpretation of all other bits in the UUID depends on the value of the variant.

In conclusion, UUIDs are practically unique, though an incredibly small potential for duplication exists. Understanding the process and implementation details of generating UUIDs can help developers better utilize these identifiers in their software development projects.

Generate uuid v4