iphone - Executing Blocks From NSArray?

Question

I was just thinking, as you can treat Blocks like objects if I create two of them and then add them to an NSArray is there a way to execute them from the array?

int (^Block_001)(void) = ^{ return 101; };
int (^Block_002)(void) = ^{ return 202; };
NSArray *array = [NSArray arrayWithObjects:Block_001, Block_002, nil];

EDIT: Update for clarity Per @davedelong's excellent answer

int (^Block_001)(void) = [^{ return 101; } copy];
int (^Block_002)(void) = [^{ return 202; } copy];
NSArray *array = [NSArray arrayWithObjects:Block_001, Block_002, nil];

[Block_001 release];
[Block_002 release];

question from:https://stackoverflow.com/questions/3257940/executing-blocks-from-nsarray

Answer 1

Sure, you just invoke it with () like any other block, but you need to typecast the value you retrieve from NSArray. Here's an example (with an added typedef, because otherwise my head hurts):

typedef int (^IntBlock)(void);
IntBlock Block_001 = ^{ return 101; };
IntBlock Block_002 = ^{ return 202; };
NSArray *array = [NSArray arrayWithObjects:Block_001, Block_002, nil];
int x = ((IntBlock)[array objectAtIndex:0]) (); // now x == 101