Question

This is a followup to my previous question.

Parsing file names from a character array

The answer was relevant but I am still having trouble. When the strings are split, I can’t seem to get them to output correctly to my error log either as a string or cstring and to be honest, I don’t completely understand how his answer works. So does anyone have a further explanation of the answer the gentleman provided. How would I split the character array into a larger number of strings rather than just writing them all out. This was the answer.

std::istringstream iss(the_array);
std::string f1, f2, f3, f4;
iss >> f1 >> f2 >> f3 >> f4;

Imagine I have 30 different strings. Surely, I can’t write f1, f2….f30.

Any advice on how to do this?

Answer 1

You can even avoid explicit for loops and try a way that is more natural to modern C++ if you will.

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <iterator>

int main()
{
   // Your files are here, separated by 3 spaces for example.
   std::string s("picture1.bmp   file2.txt   random.wtf   dance.png");

   // The stringstream will do the dirty work and deal with the spaces.
   std::istringstream iss(s);

   // Your filenames will be put into this vector.
   std::vector<std::string> v;

   // Copy every filename to a vector.
   std::copy(std::istream_iterator<std::string>(iss),
    std::istream_iterator<std::string>(),
    std::back_inserter(v));

   // They are now in the vector, print them or do whatever you want with them!
   for(int i = 0; i < v.size(); ++i)
    std::cout << v[i] << "\n";
}

This is the obvious way of dealing with a scenario like “I have 30 different strings”. Store them all somewhere, an std::vector is probably suitable, depending on what you might want to do with the filenames. This way you don’t need to give every string a name (f1, f2, …), you can just refer to them by indices of the vector if needed, for example.