CODEWITHSUNDEEP
iosobjective-carrays
Apollo
Apollo

Reputation: 9054

Join objects in sub-array into one array - Objective-c

Is there a one-liner to do the following

NSMutableArray *allpoints = [[NSMutableArray alloc] init];
for (NSMutableArray *arr in self.points)
     [allpoints addObjectsFromArray:arr];

I have an array of arrays (self.points) and I am joining all of the objects in the subarrays into a single array.

Upvotes: 1

Views: 604

Answers (4)

username tbd
username tbd

Reputation: 9382

There is not a way to add all objects in an array of arrays (e.g., every NSMutableArray in self.points to another array without iterating through.

However, you could add a category to NSArray to do exactly what you're doing now, and then call it with one line later.

Upvotes: 1

Dan Dosch
Dan Dosch

Reputation: 321

NSArray *array1 = @[ @"a", @"b", @"c" ];
NSArray *array2 = @[ @"d", @"e", @"f" ];
NSArray *array3 = @[ array1, array2 ];
NSArray * flattenedArray = [array3 valueForKeyPath:@"@unionOfArrays.self"];
NSLog(@"flattenedArray: %@", flattenedArray);

Output:

flattenedArray: ( a, b, c, d, e, f )

Upvotes: 7

Chris
Chris

Reputation: 7310

I don't think there is a way to do this. 

NSMutableArray *allpoints = [[NSMutableArray alloc] initWithArray:self.points]

would give you an array of the arrays, but there is no single line solution. I'd suggest writing a category that will do this for you so you can easily reuse it.

Upvotes: 0

endy
endy

Reputation: 3872

If you are initializing the array and adding objects at the same time then there is an initializer for that. 

NSMutableArray *allpoints = [[NSMutableArray alloc] initWithArray:self.points];

If you already have the mutable array defined and you want to just append objects to the end then you can use the following. 

[allpoints addObjectsFromArray:self.points];

Upvotes: 0

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