Mixed Arrays in C++ and C#

Question

Is it possible to create a Mixed Array in both C++ and C#

I mean an array that contains both chars and ints?

ex:

Array [][] = {{'a',1},{'b',2},{'c',3}};

A char is an integer type in C++ – Martin York Dec 08 '10 at 23:32 — Martin York, Dec 08 '10 at 23:32

score 12 · Answer 1 · edited Dec 08 '10 at 22:51

12

Neither C# nor C++ support creating this kind of data structure using native arrays, however you could create a List<Tuple<char,int>> in C# or a std::vector<std::pair<char,int>> in C++.

You could also consider using the Dictionary<> or std::map<> collections if one of the elements can be considered a unique key, and the order of the elements is unimportant but only their association.

For the case of lists (rather than dictionaries), in C# you would write:

List<Tuple<char,int>> items = new List<Tuple<char,int>>();

items.Add( new Tuple<char,int>('a', 1) );
items.Add( new Tuple<char,int>('b', 2) );
items.Add( new Tuple<char,int>('c', 3) );

and in C++ you would write:

std::vector<std::pair<char,int>> items;  // you could typedef std::pair<char,int>
items.push_back( std::pair<char,int>( 'a', 1 ) );
items.push_back( std::pair<char,int>( 'b', 2 ) );
items.push_back( std::pair<char,int>( 'c', 3 ) );

edited Dec 08 '10 at 22:51

Andrew Cooper

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answered Dec 08 '10 at 22:38

LBushkin

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instead of std::pair( 'a', 1 ) you could just use std::make_pair('a', 1), which the stdlib provides for your convenience :) – etarion Dec 08 '10 at 23:19
Why couldn't he make an array of pairs/tuples? Is there some reason I'm not seeing why his only option is to switch to List/vector? – jalf Dec 08 '10 at 23:39
@jalf STL-driven containers are likely to be less error-prone that generic arrays. – Yippie-Ki-Yay Dec 09 '10 at 22:14
True. I'm just pointing out that the "minimal" solution to the OP's problem would be to use tuple/pair. Changing the container type is irrelevant to the question, whether or not it is safer. I just think that if an answer changes the premise, it should have a good reason to do so, and explain it clearly. – jalf Dec 10 '10 at 03:40

score 5 · Answer 2 · edited May 23 '17 at 12:16

5

In C++ you would have to use something like std::vector<boost::tuple< , , > or std::vector<std::pair> if you only have two elements in each tuple.

Example for the C++ case:

typedef std::pair<int, char> Pair;

std::vector<Pair> pairs;

pairs.push_back(Pair(0, 'c'));
pairs.push_back(Pair(1, 'a'));
pairs.push_back(Pair(42, 'b'));

Extended example for the C++ case (using boost::assign).

using boost::assign;

std::vector<Pair> pairs;

pairs += Pair(0, 'c'), Pair(1, 'a'), Pair(42, 'b');

For C# you may want to see this.

edited May 23 '17 at 12:16

Community

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answered Dec 08 '10 at 22:31

Yippie-Ki-Yay

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can you give an example on how to achieve this? – sikas Dec 08 '10 at 22:34
std::vector preferred – Svisstack Dec 08 '10 at 22:34

score 0 · Answer 3 · answered Dec 08 '10 at 22:36

0

In C# and C++ it's not possible to create an array of mixed types. You should use other classes like std::vector in C++ or Dictionary <char, int> in C#.

answered Dec 08 '10 at 22:36

Dalmas

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score 0 · Answer 4 · answered Dec 08 '10 at 22:38

0

A classic array (the one with the brackets) can only have one type, which is part of its declaration (like int[] nums). There is no Array[].

answered Dec 08 '10 at 22:38

VVS

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Mixed Arrays in C++ and C#

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