CODEWITHSUNDEEP
iphoneobjective-cxcode
sharon
sharon

Reputation: 580

getting Subset of 2 arrays

I have 2 NSArray, lets call it as CountriesArray and UNCountriesArray. The CountriesArray contains all the countries in the world and the UNCountriesArray contains all the countries that belongs to the united nations.

I Want to get the subset of the 2 arrays. so finally i should get an array that has the countries that does not belong to the united nations. Can some one help me write the objective-c code that gets the subset of the 2 arrays?

Upvotes: 2

Views: 828

Answers (2)

BP.
BP.

Reputation: 10083

You can use the removeObjectsInArray method of NSMutableArray to do this. For example:

NSMutableArray *countriesArray = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", @"4", @"5", nil];
NSArray *unCountriesArray = [NSArray arrayWithObjects:@"2", @"4", nil];
[countriesArray removeObjectsInArray:unCountriesArray];
NSLog(@"Countries array: %@", countriesArray);

Upvotes: 1

Ole Begemann
Ole Begemann

Reputation: 135548

Use sets:

NSMutableSet *countriesSet = [NSMutableSet setWithArray:countriesArray];
NSSet *unSet = [NSSet setWithArray:unCountriesArray];
[countriesSet minusSet:unSet];
// countriesSet now contains only those countries who are not part of unSet

Keep in mind that the members of the set are unsorted. If you want to have a sorted array, you will have to re-sort the result.

Upvotes: 3

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