CODEWITHSUNDEEP
objective-ccocoansarray
user23790
user23790

Reputation: 563

Flatten an NSArray

I have an array like this:

array: (
    (
        "http://aaa/product/8_1371121323.png",
        "http://aaa/product/14_1371123271.png"
    ),
    (
        "http://aaa/product/9_1371121377.png"
    )
)

and I have to create another array from that one like this

array: (
    "http://aaa/product/8_1371121323.png",
    "http://aaa/product/14_1371123271.png",
    "http://aaa/product/9_1371121377.png"
)

How can I do that? Is it possible to combine all the objects and separate them using some string?

Upvotes: 22

Views: 6850

Answers (4)

Monolo
Monolo

Reputation: 18253

It can be done in a single line if you like key-value coding (KVC). The @unionOfArrays collection operator does exactly what you are looking for.

You may have encountered KVC before in predicates, bindings and similar places, but it can also be called in normal Objective-C code like this:

NSArray *flatArray = [array valueForKeyPath: @"@unionOfArrays.self"];

There are other collection operators in KVC, all prefixed with an @ sign, as discussed here.

Upvotes: 114

Andrei Shender
Andrei Shender

Reputation: 2497

Sample code:

NSArray* arrays = @(@(@"http://aaa/product/8_1371121323.png",@"http://aaa/product/14_1371123271.png"),@(@"http://aaa/product/9_1371121377.png"));
NSMutableArray* flatArray = [NSMutableArray array];
for (NSArray* innerArray in arrays) {
    [flatArray addObjectsFromArray:innerArray];
}

NSLog(@"%@",[flatArray componentsJoinedByString:@","]);

Upvotes: 1

Bhavin
Bhavin

Reputation: 27225

Sample Code :

NSMutableArray *mainArray = [[NSMutableArray alloc] init];
for (int i = 0; i < bigArray.count ; i++)
{
     [mainArray addObjectsFromArray:[bigArray objectAtIndex:i]];
}
NSLog(@"mainArray :: %@",mainArray);

Upvotes: 6

Andrey Chernukha
Andrey Chernukha

Reputation: 21808

NSMutableArray *arr1 = [NSMutableArray arrayWithArray:[initialArray objectAtIndex:0]];
[arr1 addObjectsFromArray:[initialArray objectAtIndex:1]];

Now arr1 contains all the objects

Upvotes: -1

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