Generate UUIDs in Go

package main

import (
    "fmt"
    "github.com/google/uuid"
)

func main() {
    // UUID v4 (random)
    uuid4 := uuid.New()
    fmt.Println(uuid4.String())  // Example: 3d6f9e64-7d8a-4c3e-8f2b-1a4e5c6d7e8f

    // UUID v7 (timestamp-ordered, best for databases)
    uuid7, err := uuid.NewV7()
    if err != nil {
        panic(err)
    }
    fmt.Println(uuid7.String())  // Example: 018e5e1a-7b2c-7d4f-9a3e-8c7f6e5d4c3b

    // UUID v5 (namespaced)
    namespace := uuid.NameSpaceDNS
    name := "example.com"
    uuid5 := uuid.NewSHA1(namespace, []byte(name))
    fmt.Println(uuid5.String())  // Always same: cfbff0d1-9375-5685-968c-48ce8b15ae17

    // Parse UUID from string
    uuidString := "3d6f9e64-7d8a-4c3e-8f2b-1a4e5c6d7e8f"
    parsed, err := uuid.Parse(uuidString)
    if err != nil {
        fmt.Println("Invalid UUID")
    }
    fmt.Println("Version:", parsed.Version())  // Outputs: 4

    // Generate multiple UUIDs
    for i := 0; i < 5; i++ {
        fmt.Println(uuid.New())
    }

    // Nil UUID
    nilUUID := uuid.Nil
    fmt.Println(nilUUID)  // 00000000-0000-0000-0000-000000000000
}

// Install: go get github.com/google/uuid