3

Let's say I have two arrays:

NSArray * first = @[@"One", @"Two", @"Three"," @Four"];
NSArray * second = @[@"Four", @"Five", @"Six", @"One"];

I want to put the objects that are in both into another array:

NSArray * both = @[@"Four", @"One"];

Is there a more elegant way than going through each item of the first one and checking if its contained in the second?

jscs
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DanielR
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3 Answers3

9

You basically need to find the intersection of the arrays so you need to use set here:

NSMutableSet *intersection = [NSMutableSet setWithArray:firstArray];
[intersection intersectSet:[NSSet setWithArray:secondArray]];

NSArray *resultArray = [intersection allObjects];
Saurabh Passolia
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1

Create 2 instances of NSMutableSet from your 2 arrays. Then do:

NSArray *result = [[set1 intersectSet:set2] allObjects];
Wain
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1

Sure. Just use the right tool for the right task. Alias, use sets for set operations.

NSSet *first = [NSSet setWithArray:array1];
NSMutableSet *second = [NSMutableSet setWithArray:array2];
[second intersectSet:first];
NSArray *commonObjects = [second allObjects];