macOS The Difference Between NIL and NULL...

[Darkroom]

... is what exactly?

 

[lee1210]

Style.

They will both be compiled to 0.

From what I can tell the stylistic difference is that NULL is used to indicate a null pointer to a primitive type, and nil is used to indicate a null pointer to an Object.

-Lee

 

[TimJim]

NIL is no value/zero. We're winning 5-nil
NULL is the absence of data (when writing software)

 

[iSee]

Assuming we're talking about Objetive-C:
nil (all lower-case) is a null pointer to an Objective-C object.
Nil (capitalized) is a null pointer to an Objective-C class.
NULL (all caps) is a null pointer to anything else.

So, conceptually, they mean the same thing but for different categories of things. They all have the same representation, too; they all happen to have the numeric value of 0.

I don't know whether or not NIL (all upper-case) has special meaning in Objective-C.

 

[NSNick]

Darkroom, I believe on your avatar, the letter immediately following NS should be capitalized.

 

[Darkroom]

Darkroom, I believe on your avatar, the letter immediately following NS should be capitalized.

but then it would be an ex-object... and NSSexObject doesn't play with the term/concept as much... anyway...🙄

Assuming we're talking about Objetive-C:
nil (all lower-case) is a null pointer to an Objective-C object.
Nil (capitalized) is a null pointer to an Objective-C class.
NULL (all caps) is a null pointer to anything else.

So, conceptually, they mean the same thing but for different categories of things. They all have the same representation, too; they all happen to have the numeric value of 0.

I don't know whether or not NIL (all upper-case) has special meaning in Objective-C.

so to get this straight...??

[NSApp beginSheet:sheet
   modalForWindow:mainWindow
      modalDelegate:nil                 [COLOR="SeaGreen"]//pointing to an [I]object[/I] (modelDelegate?) and making it zero?[/COLOR]
      didEndSelector:NULL             [COLOR="SeaGreen"]//pointing to a [I]non object/class[/I] and making it zero?[/COLOR]
           contextInfo:NULL];           [COLOR="SeaGreen"]//pointing to a [I]non object/class[/I] and making it zero?[/COLOR]

 

[Catfish_Man]

That looks correct.

 

[HiRez]

Don't forget NSNull!

 

[stimpy77]

Don't forget NSNull!

Please share.

EDIT: Nevermind.

http://developer.apple.com/documentation/Cocoa/Conceptual/NumbersandValues/Articles/Null.html

NSNull is a singleton object used to represent a null value where nil is prohibited, namely collections. I come from the Windows world, this kinda reminds me of System.DBNull in C# ...

 

[Littleodie914]

Yea, the different types can get confusing at times. In all my experience, I've only used the "nil" and "NULL" keywords, referring to an objective-c object pointer, and a primitive type pointer, respectively. I've never needed anything else, but maybe I just haven't gotten deep enough. 😀

 

[certsoft]

NIL is a reserved word in Pascal, I don't know what it would be doing in C (although I've never used objective C). Like NULL, it's value is usually zero.