Using block-based dictionary enumeration to find a matching key

gistfile1.m

__block Foo *result = nil;
[dictionary enumerateKeysAndObjectsUsingBlock:^(id aKey, id anObject, BOOL *stop) {
    
    BOOL matches = ... // test if key meets requirements here
    if (matches)
    {
        result = anObject;
        *stop = YES;
    }
}];