NSBlock class is a concrete subclass of
Operation that manages the concurrent execution of one or more blocks. You can use this object to execute several blocks at once without having to create separate operation objects for each. When executing more than one block, the operation itself is considered finished only when all blocks have finished executing.
- iOS 4.0+
- macOS 10.6+
- tvOS 9.0+
- watchOS 2.0+
Blocks added to a block operation are dispatched with default priority to an appropriate work queue. The blocks themselves should not make any assumptions about the configuration of their execution environment.
For more information about blocks, see Blocks Programming Topics.