syntax - What does the @ symbol mean for Objective-C? -

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i know following uses of @ (at symbol):

@"mystring" - used indicate objective-c nsstring, rather standard c string

@keyword - used identify objective c keywords such @implementation, @synthesize, @class , @interface

what @keyname mean in context below?

[sfhfkeychainutils storeusername:@keyname andpassword:[nsstring stringwithutf8string:b64data] forservicename:@"default" updateexisting:yes error:&ter_ror];

does @ have other possible meanings?

it means nothing @ in context of code snippet. fail syntax error.

the reason @ used in obj-c keywords , in constant strings because @ not valid character use part of token in c, , obj-c strict superset of c. means valid c code valid obj-c code, obj-c can't take keywords have possibly shown in valid c. since @ isn't valid in tokens, means obj-c use start of keywords , not worry collisions.

as other possible meanings, there few keywords omitted, such @protocol, @dynamic, @private, @protected, @public, @selector, , @encode.


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