What does the @ symbol mean for Objective-C?

Question

I know the following uses of @ (with character):

@ "myString" - used to specify objective-c NSString, not standard C string

@keyword - used to define some objective c keywords, such as @implementation, @synthesize, @class and @interface

What does @KEYNAME mean in the context below?

[SFHFKeychainUtils storeUsername:@KEYNAME andPassword:[NSString stringWithUTF8String:b64data] forServiceName:@"default" updateExisting:YES error:&ter_ror];

Does @ have other possible meanings?

Answer 1

This does not mean anything at all in the context of a piece of code. This will result in a syntax error.

@ Obj-C , @ , C, Obj-C - C. , C Obj-C, Obj-C - , C. @ , , Obj-C .

, , , @protocol, @dynamic, @private, @protected, @public, @selector @encode.