vector2dim.cpp

#include <iostream>
#include <vector>
int main()
{
    std::vector <            // I want a vector 
        std::vector<double>  // each element of the vector is a vector
        > variableName       // name of the vector
        (5, // how many elements in the frist dimension
         std::vector<double>(2) // It knows each element is a vector (the subvectors. Here we say exactly
                                // what size each subvector to create
            );
   std::cout  << "Size first dimension : " << variableName.size() << std::endl;
   std::cout  << "Size second dimension : " << variableName[0].size() << std::endl;
}