printing content of an array into .txt file-CodePudding

the ifstream part(reading .csv file into array) works perfectly but the ofstream part(printing array into .txt file) gives error. got error no match for 'operator<<'

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
#include <iomanip>

using namespace std;

int main()
{

    ifstream in("test.csv");

    string line, field;

    vector <vector <string>> array;
    vector <string> v;

    while (getline(in, line))
    {
        v.clear();
        stringstream ss(line);

        while(getline(ss,field,','))
        {
            v.push_back(field); 

        }

        array.push_back(v);

    }
    
    
    ofstream myfile("test1.txt");
    myfile<<array;
    myfile.close();

error message:

error: no match for 'operator<<' (operand types are 'std::ofstream' {aka  'std::basic_ofstream<char>'} and 'std::vector<std::vector<std::__cxx11::basic_string<char> > >')

CodePudding user response：

There is no operator overloaded for the std::vector<std::vector<std::string>> in the std::ofstream, so you can't do that. One way you could do this is:

std::ofstream myfile("test1.txt");
if (myfile)
{
    //https://www.cplusplus.com/reference/ostream/ostream/write/
    for (auto& elem : array)
    {
        for (auto& str : elem)
        {
            myfile.write(str.data(), str.size());
        }
    }

    myfile.close();
}

I would prefer JSON, for serializing this type of stuff.