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< span > uuid</ span >
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< article >
< h1 > uuid</ h1 >
< p > The < code > uuid</ code > module provides UUID (Universally Unique Identifier) generation and validation. It supports version 4 UUIDs which are randomly generated.</ p >
< pre >< code > import "uuid" for Uuid</ code ></ pre >
< h2 > Uuid Class</ h2 >
< div class = "class-header" >
< h3 > Uuid</ h3 >
< p > UUID generation and validation</ p >
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< h3 > Static Methods</ h3 >
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< span class = "method-name" > Uuid.v4</ span > () → < span class = "type" > String</ span >
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< p > Generates a new random version 4 UUID.</ p >
< ul class = "param-list" >
< li >< span class = "returns" > Returns:</ span > A 36-character UUID string in the format < code > xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx</ code ></ li >
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< pre >< code > var id = Uuid.v4()
System.print(id) // e.g., "550e8400-e29b-41d4-a716-446655440000"</ code ></ pre >
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< span class = "method-name" > Uuid.isValid</ span > (< span class = "param" > string</ span > ) → < span class = "type" > Bool</ span >
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< p > Checks if a string is a valid UUID format (any version).</ p >
< ul class = "param-list" >
< li >< span class = "param-name" > string</ span > < span class = "param-type" > (String)</ span > - The string to validate</ li >
< li >< span class = "returns" > Returns:</ span > < code > true</ code > if the string is a valid UUID format, < code > false</ code > otherwise</ li >
</ ul >
< pre >< code > System.print(Uuid.isValid("550e8400-e29b-41d4-a716-446655440000")) // true
System.print(Uuid.isValid("not-a-uuid")) // false
System.print(Uuid.isValid("550e8400e29b41d4a716446655440000")) // false (missing hyphens)</ code ></ pre >
< div class = "method-signature" >
< span class = "method-name" > Uuid.isV4</ span > (< span class = "param" > string</ span > ) → < span class = "type" > Bool</ span >
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< p > Checks if a string is a valid version 4 UUID.</ p >
< ul class = "param-list" >
< li >< span class = "param-name" > string</ span > < span class = "param-type" > (String)</ span > - The string to validate</ li >
< li >< span class = "returns" > Returns:</ span > < code > true</ code > if the string is a valid v4 UUID, < code > false</ code > otherwise</ li >
</ ul >
< pre >< code > var id = Uuid.v4()
System.print(Uuid.isV4(id)) // true
System.print(Uuid.isV4("550e8400-e29b-11d4-a716-446655440000")) // false (version 1)</ code ></ pre >
< h2 > UUID Format</ h2 >
< p > UUIDs are 128-bit identifiers represented as 32 hexadecimal characters separated by hyphens into five groups:</ p >
< pre >< code > xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
8 4 4 4 12 = 32 hex chars + 4 hyphens = 36 chars</ code ></ pre >
< table >
< tr >
< th > Position</ th >
< th > Description</ th >
</ tr >
< tr >
< td > M</ td >
< td > Version number (4 for v4 UUIDs)</ td >
</ tr >
< tr >
< td > N</ td >
< td > Variant (8, 9, a, or b for RFC 4122 UUIDs)</ td >
</ tr >
</ table >
< h2 > Examples</ h2 >
< h3 > Generating Unique Identifiers</ h3 >
< pre >< code > import "uuid" for Uuid
var userId = Uuid.v4()
var sessionId = Uuid.v4()
System.print("User ID: %(userId)")
System.print("Session ID: %(sessionId)")</ code ></ pre >
< h3 > Validating User Input</ h3 >
< pre >< code > import "uuid" for Uuid
var input = "550e8400-e29b-41d4-a716-446655440000"
if (Uuid.isValid(input)) {
System.print("Valid UUID")
if (Uuid.isV4(input)) {
System.print("This is a v4 UUID")
}
} else {
System.print("Invalid UUID format")
}</ code ></ pre >
< h3 > Using with Database Records</ h3 >
< pre >< code > import "uuid" for Uuid
class User {
construct new(name) {
_id = Uuid.v4()
_name = name
}
id { _id }
name { _name }
}
var user = User.new("Alice")
System.print("Created user %(user.name) with ID %(user.id)")</ code ></ pre >
< div class = "admonition note" >
< div class = "admonition-title" > Note</ div >
< p > Version 4 UUIDs are generated using cryptographically secure random bytes from the < code > crypto</ code > module. The probability of generating duplicate UUIDs is astronomically low.</ p >
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