檢查兩個NSArray之間的NSDictionaries之間的共同價值

Question

我有兩個NSArray，notiCloud和notiLoc，都與NSDictonary具有相同的結構。我需要知道如何檢查兩個NSArray中有多少NSDictionary，例如使用密鑰@「id」。

非常感謝。

Answer 1

// Create arrays of the IDs only 
NSArray *notiCloudIDs = [notiCloud valueForKey:@"id"]; 
NSArray *notiLocIDs = [notiLoc valueForKey:@"id"]; 

// Turn the arrays into sets and intersect the two sets 
NSMutableSet *notiCloudIDsSet = [NSMutableSet setWithArray:notiCloudIDs]; 
NSMutableSet *notiLocIDsSet = [NSMutableSet setWithArray:notiLocIDs]; 
[notiCloudIDsSet intersectSet:notiLocIDsSet]; 

// The IDs that are now in notiCloudIDsSet have been present in both arrays 
NSLog(@"Duplicate IDs: %@", notiCloudIDsSet);