Concatenation of two arrays in Objective-C

Question

How to concatenate two arrays into a single array in Objective-C?

Answer 1

NSArray* newArray = [firstArray arrayByAddingObjectsFromArray:secondArray];

Or using mutable array version just add to it all objects from another array:

[myMutableArray addObjectsFromArray:secondArray];

Answer 2

With immutable arrays:

NSArray *arr1 = @[@(1), @(2), @(3)];
NSArray *arr2 = @[@(4), @(5), @(6)];
NSArray *arr3 = [arr1 arrayByAddingObjectsFromArray:arr2];

or adding onto a mutable array:

NSArray *arr1 = @[@(1), @(2), @(3)];
NSArray *arr2 = @[@(4), @(5), @(6)];
NSMutableArray *arr3 = [NSMutableArray arrayWithArray:arr1];

[arr3 addObjectsFromArray:arr2];

Answer 3

NSSArray *theArrayIReallyWant = [oneArrayIDontReallyWant arrayByAddingObjectsFromArray:otherArrayIDontReallyWant];

If you need to, retain theArrayIReallyWant so it stays in memory, just be sure to release it when you are done. That by far is the easiest method :)