[ios] How to create a GUID/UUID using iOS

I want to be able to create a GUID/UUID on the iPhone and iPad.

The intention is to be able to create keys for distributed data that are all unique. Is there a way to do this with the iOS SDK?

Reviewing the Apple Developer documentation I found the CFUUID object is available on the iPhone OS 2.0 and later.

Here is the simple code I am using, compliant with ARC.

+(NSString *)getUUID
{
    CFUUIDRef newUniqueId = CFUUIDCreate(kCFAllocatorDefault);
    NSString * uuidString = (__bridge_transfer NSString*)CFUUIDCreateString(kCFAllocatorDefault, newUniqueId);
    CFRelease(newUniqueId);

    return uuidString;
}

I've uploaded my simple but fast implementation of a Guid class for ObjC here: obj-c GUID

Guid* guid = [Guid randomGuid];
NSLog("%@", guid.description);

It can parse to and from various string formats as well.

Reviewing the Apple Developer documentation I found the CFUUID object is available on the iPhone OS 2.0 and later.

Reviewing the Apple Developer documentation I found the CFUUID object is available on the iPhone OS 2.0 and later.

In iOS 6 you can easily use:

NSUUID  *UUID = [NSUUID UUID];
NSString* stringUUID = [UUID UUIDString];

More details in Apple's Documentations

In Swift 3.0

var uuid = UUID().uuidString

In Swift 3.0

var uuid = UUID().uuidString

Here is the simple code I am using, compliant with ARC.

+(NSString *)getUUID
{
    CFUUIDRef newUniqueId = CFUUIDCreate(kCFAllocatorDefault);
    NSString * uuidString = (__bridge_transfer NSString*)CFUUIDCreateString(kCFAllocatorDefault, newUniqueId);
    CFRelease(newUniqueId);

    return uuidString;
}

In iOS 6 you can easily use:

NSUUID  *UUID = [NSUUID UUID];
NSString* stringUUID = [UUID UUIDString];

More details in Apple's Documentations

The simplest technique is to use NSString *uuid = [[NSProcessInfo processInfo] globallyUniqueString]. See the NSProcessInfo class reference.

In Swift:

var uuid: String = NSUUID().UUIDString
println("uuid: \(uuid)")

I've uploaded my simple but fast implementation of a Guid class for ObjC here: obj-c GUID

Guid* guid = [Guid randomGuid];
NSLog("%@", guid.description);

It can parse to and from various string formats as well.

The simplest technique is to use NSString *uuid = [[NSProcessInfo processInfo] globallyUniqueString]. See the NSProcessInfo class reference.