CODEWITHSUNDEEP
multidimensional-arrayswift
user1107173
user1107173

Reputation: 10744

Multidimensional arrays From C to Swift

In C I have the following multidimensional array:

unsigned wins[8][3] = {{0,1,2},{3,4,5},{6,7,8},{0,3,6},{1,4,7},{2,5,8},{0,4,8},{2,4,6}};

To access the elements I use the following code:

int i;
for(i = 0; i < 8; ++i)     {
    unsigned *positions;
    positions = wins[i];

    unsigned pos0 = positions[0];
    unsigned pos1 = positions[1];
    unsigned pos2 = positions[2];

    if(arrayPassedIn[pos0] != 0 && arrayPassedIn[pos0] == arrayPassedIn[pos1] && arrayPassedIn[pos0] == arrayPassedIn[pos2])
    {
         // Do Something Here
    }

I know in swift I can do something like:

var array = Array<Array<Int>>()

But I'm not sure if this produces the same result for accessing the elements.

Upvotes: 3

Views: 203

Answers (2)

Mike S
Mike S

Reputation: 42325

You can create a multi-dimentsional array in a pretty similar manner to your C code:

var wins = [[0,1,2],[3,4,5],[6,7,8],[0,3,6],[1,4,7],[2,5,8],[0,4,8],[2,4,6]]

The Swift code to use it the same way as your C code is also pretty similar; the main difference is using a for-in loop instead of the standard for loop (although you could do that too).

for positions in wins {
    var pos0 = positions[0]
    var pos1 = positions[1]
    var pos2 = positions[2]

    if(arrayPassedIn[pos0] != 0 && arrayPassedIn[pos0] == arrayPassedIn[pos1] && arrayPassedIn[pos0] == arrayPassedIn[pos2])
    {
        // Do Something Here
    }
}

Do note that, even though there are similarities, Arrays in Swift are not like arrays in C. For instance, when you're looping over wins, you're actually creating copies of the positions arrays (the actual memory copy only happens if you write to the array, so there's not really a performance penalty). If you then set, say, positions[0] to a different value, that value would not be updated in wins like it would if this were C.

Upvotes: 3

Steve Rosenberg
Steve Rosenberg

Reputation: 19524

I have never worked in obj-C, but in swift I think the equivalent is:

let array: [(Int, Int, Int)] = [(0,1,2),(3,4,5),(6,7,8),(0,3,6),(1,4,7),(2,5,8),(0,4,8),(2,4,6)]
println(array[2].0) //6

Upvotes: 1

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