    [[UIDevice currentDevice] uniqueIdentifier]

Returns the Unique ID of your iPhone.

&gt; EDIT: `-[UIDevice uniqueIdentifier]` is now deprecated and apps are being rejected from the App Store for using it. The method below is now the preferred approach.


If you need to create several UUID, just use this method (with ARC):

    + (NSString *)GetUUID
    {
      CFUUIDRef theUUID = CFUUIDCreate(NULL);
      CFStringRef string = CFUUIDCreateString(NULL, theUUID);
      CFRelease(theUUID);
      return (__bridge NSString *)string;
    }

EDIT: Jan, 29 2014:
If you&#39;re targeting iOS 6 or later, you can now use the much simpler method:

    NSString *UUID = [[NSUUID 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&#39;s Documentations][1]


  [1]: http://developer.apple.com/library/mac/#documentation/Foundation/Reference/NSUUID_Class/Reference/Reference.html

Reviewing the Apple Developer documentation I found the [CFUUID][1] object is available on the iPhone OS 2.0 and later. 


  [1]: http://developer.apple.com/library/mac/documentation/CoreFoundation/Reference/CFUUIDRef/Reference/reference.html

In **Swift**:

    var uuid: String = NSUUID().UUIDString
    println(&quot;uuid: \(uuid)&quot;)



The simplest technique is to use `NSString *uuid = [[NSProcessInfo processInfo] globallyUniqueString]`. See the [NSProcessInfo][1] class reference.

[1]:http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/Foundation/Classes/NSProcessInfo_Class/Reference/Reference.html#//apple_ref/doc/uid/20000316-globallyUniqueString

In **Swift 3.0**

    var uuid = UUID().uuidString

I&#39;ve uploaded my simple but fast implementation of a Guid class for ObjC here: [obj-c GUID][1]

    Guid* guid = [Guid randomGuid];
    NSLog(&quot;%@&quot;, guid.description);


It can parse to and from various string formats as well.


  [1]: https://code.google.com/p/objc-guid/source/browse/

I want to be able to edit one method while looking at another method in the same file, as reference.
Can this be done?

Visual Studio: How can I see the same file in two separate tab groups?

Can anyone explain why following code won&#39;t compile? At least on g++ 4.2.4.

And more interesting, why it will compile when I cast MEMBER to int?

    #include &lt;vector&gt;

    class Foo {  
    public:  
        static const int MEMBER = 1;  
    };

    int main(){  
        vector&lt;int&gt; v;  
        v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER&#39;
        v.push_back( (int) Foo::MEMBER ); // OK  
        return 0;
    }


Undefined reference to static class member

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?


How to create a GUID/UUID using iOS

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


How can I set the maximum amount of characters in a `UITextField` on the iPhone SDK when I load up a `UIView`?

Set the maximum character length of a UITextField

I am creating a free version of my iPhone game. I want to have a button inside the free version that takes people to the paid version in the app store. If I use a standard link

http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=300136119&amp;mt=8

the iPhone opens Safari first, and then the app store. I have used other apps that open the app store directly, so I know it is possible.

Any ideas? What is the URL Scheme for the app store?


How to link to apps on the app store

I&#39;m creating a color object using the following code.

    curView.backgroundColor = [[UIColor alloc] initWithHue:229 saturation:40 brightness:75 alpha:1];

How can I retrieve RGB values from the created color object?

How to get RGB values from UIColor?

Any ideas as to how Apple implemented the &quot;slide to unlock&quot; (also, &quot;slide to power off&quot; is another identical example) animation?

I thought about some sort of animating mask - but masking is not available on the iPhone OS for performance reasons.

Is there some private API effect (like SuckEffect) that they might have used? A spotlight type of effect?  Some Core Animation thing?

Edit:
It&#39;s definitely not a series of stills.  I&#39;ve seen examples of being edit a plist value or something and customize the string on jailbroken iphones.

iPhone &quot;slide to unlock&quot; animation

Consider I have the following text in a `UILabel` (a long line of dynamic text):

&gt; Since the alien army vastly outnumbers the team, players must use the post-apocalyptic world to their advantage, such as seeking cover behind dumpsters, pillars, cars, rubble, and other objects. 

I want to resize the `UILabel&#39;s` height so that the text can fit in. I&#39;m using following properties of `UILabel` to make the text within to wrap.

    myUILabel.lineBreakMode = UILineBreakModeWordWrap;
    myUILabel.numberOfLines = 0;

Please let me know if I&#39;m not heading in the right direction. Thanks.

Adjust UILabel height depending on the text

How do I create a GUID in Python that is platform independent? I hear there is a method using ActivePython on Windows but it&#39;s Windows only because it uses COM. Is there a method using plain Python?


How to create a GUID/UUID in Python

What is the best way to programmatically generate a GUID or UUID in C++ without relying on a platform-specific tool? I am trying to make unique identifiers for objects in a simulation, but can&#39;t rely on Microsoft&#39;s implementation as the project is cross-platform.

Notes: 

 - Since this is for a simulator, I
   don&#39;t really need cryptographic
   randomness. 
 - It would be best if this is a 32 bit number.





Platform-independent GUID generation in C++?

I don&#39;t really see the point of [UUID][1].  I know the probability of a collision is *effectively nil*, but *effectively nil* is not even close to impossible.

Can somebody give an example where you have no choice but to use UUID?  From all the uses I&#39;ve seen, I can see an alternative design without UUID.  Sure the design might be slightly more complicated, but at least it doesn&#39;t have a non-zero probability of failure.

UUID smells like global variables to me.  There are many ways global variables make for simpler design, but its just lazy design.

  [1]: http://en.wikipedia.org/wiki/UUID

When are you truly forced to use UUID as part of the design?

I have been experimenting with using UUIDs as database keys.  I want to take up the least amount of bytes as possible, while still keeping the UUID representation human readable.

I think that I have gotten it down to 22 bytes using base64 and removing some trailing &quot;==&quot; that seem to be unnecessary to store for my purposes.  Are there any flaws with this approach?  

Basically my test code does a bunch of conversions to get the UUID down to a 22 byte String, then converts it back into a UUID.

    import java.io.IOException;
    import java.util.UUID;
    
    public class UUIDTest {
    
    	public static void main(String[] args){
    		UUID uuid = UUID.randomUUID();
    		System.out.println(&quot;UUID String: &quot; + uuid.toString());
    		System.out.println(&quot;Number of Bytes: &quot; + uuid.toString().getBytes().length);
    		System.out.println();
    		
    		byte[] uuidArr = asByteArray(uuid);
    		System.out.print(&quot;UUID Byte Array: &quot;);
    		for(byte b: uuidArr){
    			System.out.print(b +&quot; &quot;);
    		}
    		System.out.println();
    		System.out.println(&quot;Number of Bytes: &quot; + uuidArr.length);
    		System.out.println();
    		
    		
    	    try {
    	        // Convert a byte array to base64 string
    	        String s = new sun.misc.BASE64Encoder().encode(uuidArr);
    	        System.out.println(&quot;UUID Base64 String: &quot; +s);
    	        System.out.println(&quot;Number of Bytes: &quot; + s.getBytes().length);
    	        System.out.println();
    	        
    	        
    	        String trimmed = s.split(&quot;=&quot;)[0];
    	        System.out.println(&quot;UUID Base64 String Trimmed: &quot; +trimmed);
    	        System.out.println(&quot;Number of Bytes: &quot; + trimmed.getBytes().length);
    	        System.out.println();
    	        
    	        // Convert base64 string to a byte array
    	        byte[] backArr = new sun.misc.BASE64Decoder().decodeBuffer(trimmed);
    			System.out.print(&quot;Back to UUID Byte Array: &quot;);
    			for(byte b: backArr){
    				System.out.print(b +&quot; &quot;);
    			}
    			System.out.println();
    			System.out.println(&quot;Number of Bytes: &quot; + backArr.length);
    			
    			byte[] fixedArr = new byte[16];
    			for(int i= 0; i&lt;16; i++){
    				fixedArr[i] = backArr[i];
    			}
    			System.out.println();
    			System.out.print(&quot;Fixed UUID Byte Array: &quot;);
    			for(byte b: fixedArr){
    				System.out.print(b +&quot; &quot;);
    			}
    			System.out.println();
    			System.out.println(&quot;Number of Bytes: &quot; + fixedArr.length);
    			
    			System.out.println();
    			UUID newUUID = toUUID(fixedArr);
    			System.out.println(&quot;UUID String: &quot; + newUUID.toString());
    			System.out.println(&quot;Number of Bytes: &quot; + newUUID.toString().getBytes().length);
    			System.out.println();
    			
    			System.out.println(&quot;Equal to Start UUID? &quot;+newUUID.equals(uuid));
    			if(!newUUID.equals(uuid)){
    				System.exit(0);
    			}
    			
    			
    	    } catch (IOException e) {
    	    }
    
    	}
    	
    	
    	public static byte[] asByteArray(UUID uuid) {
    
    		long msb = uuid.getMostSignificantBits();
    		long lsb = uuid.getLeastSignificantBits();
    		byte[] buffer = new byte[16];
    
    		for (int i = 0; i &lt; 8; i++) {
    			buffer[i] = (byte) (msb &gt;&gt;&gt; 8 * (7 - i));
    		}
    		for (int i = 8; i &lt; 16; i++) {
    			buffer[i] = (byte) (lsb &gt;&gt;&gt; 8 * (7 - i));
    		}
    
    		return buffer;
    
    	}
    	
    	public static UUID toUUID(byte[] byteArray) {
    
    		long msb = 0;
    		long lsb = 0;
    		for (int i = 0; i &lt; 8; i++)
    			msb = (msb &lt;&lt; 8) | (byteArray[i] &amp; 0xff);
    		for (int i = 8; i &lt; 16; i++)
    			lsb = (lsb &lt;&lt; 8) | (byteArray[i] &amp; 0xff);
    		UUID result = new UUID(msb, lsb);
    
    		return result;
    	}
    	
    }

output:

    UUID String: cdaed56d-8712-414d-b346-01905d0026fe
    Number of Bytes: 36
    
    UUID Byte Array: -51 -82 -43 109 -121 18 65 77 -77 70 1 -112 93 0 38 -2 
    Number of Bytes: 16
    
    UUID Base64 String: za7VbYcSQU2zRgGQXQAm/g==
    Number of Bytes: 24
    
    UUID Base64 String Trimmed: za7VbYcSQU2zRgGQXQAm/g
    Number of Bytes: 22
    
    Back to UUID Byte Array: -51 -82 -43 109 -121 18 65 77 -77 70 1 -112 93 0 38 -2 0 38 
    Number of Bytes: 18
    
    Fixed UUID Byte Array: -51 -82 -43 109 -121 18 65 77 -77 70 1 -112 93 0 38 -2 
    Number of Bytes: 16
    
    UUID String: cdaed56d-8712-414d-b346-01905d0026fe
    Number of Bytes: 36
    
    Equal to Start UUID? true



Storing UUID as base64 String

How safe is it to use UUID to uniquely identify something (I&#39;m using it for files uploaded to the server)? As I understand it, it is based off random numbers. However, it seems to me that given enough time, it would eventually repeat it self, just by pure chance. Is there a better system or a pattern of some type to alleviate this issue?

How unique is UUID?

I know this may sounds like a pointless question, but hear me out...

I basically want to know if I can trust the GUID to generate a value which will be unique 100% of the time and impossible to predict.

I&#39;m basically rolling my on login system for a website and want to know if the GUID is secure enough for session cookies.

Any background on how the GUID is generated would be much appreciated in evaluating the answers.

**Thanks for the links to duplicate questions, however, my question is specific to the .Net framework.**

How Random is System.Guid.NewGuid()?

I need to access the assembly of my project in C# .NET 2.0.

I can see the GUID in the &#39;Assembly Information&#39; dialog in under project properties, and at the moment I have just copied it to a const in the code. The GUID will never change, so this is not that bad of a solution, but it would be nice to access it directly. Is there a way to do this?


How do I programmatically get the GUID of an application in .NET 2.0

Using ASCII encoding, how many characters are there in a GUID?

I&#39;m interested in the Microsoft style, which includes the curly brackets and dashes.

Content Type	Original Author	Original Content on Stackoverflow
Question	rustyshelf	View Question on Stackoverflow
Solution 1 - Ios	Stephan Burlot	View Answer on Stackoverflow
Solution 2 - Ios	trillions	View Answer on Stackoverflow
Solution 3 - Ios	Arian Sharifian	View Answer on Stackoverflow
Solution 4 - Ios	Henk	View Answer on Stackoverflow
Solution 5 - Ios	King-Wizard	View Answer on Stackoverflow
Solution 6 - Ios	Ryan McCuaig	View Answer on Stackoverflow
Solution 7 - Ios	Radu Diță	View Answer on Stackoverflow
Solution 8 - Ios	tumtumtum	View Answer on Stackoverflow

How to create a GUID/UUID using iOS

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

Solution 3 - Ios

Solution 4 - Ios

Solution 5 - Ios

Solution 6 - Ios

Solution 7 - Ios

Solution 8 - Ios

Undefined reference to static class member

Visual Studio: How can I see the same file in two separate tab groups?

Attributions