Question

My program is written in C++.

#include <iostream>
#include <string>
#include <map>

using namespace std;


    class Details
    {
        int x;
        int y;
    };

    typedef std::map<string, Details> Det;
    Det det;

    Details::Details(int p, int c) {
        x = p;
        y = c;
    }

    int main(){

        det.clear();

        insertNew("test", 1, 2);

        cout << det["test"] << endl;

        return 0;
    }

I want to print the value of a key with the simplest way. Eg det[“test”] fails to compile.
How to I print values (1,2) for (x,y) that correspond to key “test”?

Answer 1

My best guess is that you have no default or copy constructor in your Obj (you don’t have any in the code you posted, but I assume you have one that takes two integers). You’ve also got a typo in the catalog.insert() line. Here is what worked for me, using your code:

class Obj {
public:
    Obj() {}
    Obj(int x, int y) : x(x), y(y) {}
    int x;
    int y; 
   };


int main (int argc, char ** argv) {

    std::map<std::string, Obj> catalog; 
    catalog.insert(std::map<std::string, Obj>::value_type("test", Obj(1,2)));

    std::cout << catalog["test"].x << " " << catalog["test"].y << std::endl;

    return 0;
}