Caret in objective C

What doe开发者_Go百科s the caret in objective C mean?

ie.

void (^handler)(NSInteger);

from Mac Dev Center

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It depends on the context. In the example you show, it's used to denote a Block. The caret symbol is also the bitwise XOR operator in C-based languages — that's what most programmers would identify it as, so it's good to understand that it can be both depending on where it appears, much like *, etc.

And while we're suggesting references, one simply has to include Apple's official Blocks reference.

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The caret represents a block or a closure which carries around or contains the lexical scope. They are similar to blocks in ruby. An excellent reference can be found here.

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Like ennuikiller said, it indicates a block. If you want to learn more, Ars Technica had an excellent in-depth review of Snow Leopard that described not only blocks and closures, but also Grand Central Dispatch and all the other new technologies in Mac OS X 10.6. Highly recommended.