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I am trying to create a multidimensional array in c++ where there's a string and an int involved. I tried int test[1][2] = {{"a", 1}, {"b", 2}, {"c", 3}}; but g++ gave me the following:

example.cpp: In function ‘int getServer(std::string)’:
error: too many initializers for ‘int [1][2]’
error: invalid conversion from ‘const char*’ to ‘int’ [-fpermissive]

I tried to use char test[1][2] as well for the initializer, but this didn't work.

Edit: This will become a rather large multidimensional array and it's needed so that I can get values and store based on a loop control variable which will vary in its length.

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  • Are you mapping one to another or storing pairs? Commented Aug 27, 2013 at 15:36
  • basically trying to store them in pairs to access each value doing something like test[0][0] Commented Aug 27, 2013 at 15:38

3 Answers 3

Reset to default
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Use std::pair:

std::array<std::pair<std::string, int>, 3> test{{"a", 1}, {"b", 2}, {"c", 3}};

std::pair works with C++03, but the initialization and array type I used are C++11. You can still use a normal array and a bunch of std::make_pair calls.

Now you can access each inner element with an index and first or second:

test[0].first //"a"
test[2].second //3
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4 Comments

well, I need to be able to use the multidimensional array to get the length (by that, I mean the number of pairs), and also be able to use it in cases like while (i <= 10) { test[0][i]; i++; }
@cellsheet, You can get the number of pairs with test.size(). As for your other example, pairs only have two "elements", so i <= 10 doesn't make sense. And with only two, I can't imagine why you would specifically make it harder to use [i] than just .first, followed by .second.
there's a specific formula I have to port in which it heavily rely's on the length of the array and stores/access values depending on the loop control variable. while (length < test.size()) { variable += test[variable2][1]; variable++; } is an example of part of this formula.
@cellsheet, The only thing you need to change to make it work is the constant [1] to a constant .second.
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This is not allowed in c++. An array can only have one type, so specifying an array with two types like that does not actually make sense.

My idea to do this would be to define a struct:

struct pair {
    std::string s;
    int i;
}

And then define a one dimensional array of type pair. Then access your elements like array[0].s

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1 Comment

To store a collection of multiple types, I would use a tuple instead of an array.
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This generally should not be done in C++. If you are associating pairs (chars and ints, for example), and want them in an array, you should use a simple struct to associate the two, like 

struct MyPair {
   char letter;
   int number;
};

Then use it like this:

MyPair pairAr[2];
MyPair myPair;
myPair.letter = 'a';
myPair.number = 1;
pairAr[0] = myPair;

This is generally more a C style. You also may want to consider making a class which contains the information you want, and using STL collections, like the Vector class.

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