Best way to read a files contents and separate different data types into separate vectors in C-CodePudding

I'm fairly new to the C syntax and wondered if someone could provide how they would approach a problem I have.

My task is to read a files txt contents which contains a combination of strings and integers. I then need to store all the integers into one vector and all strings into another vector. I have managed to store all the contents into a vector, but now I want to separate the different data types into their own vectors, however I'm struggling to find the best approach for this. Would I iterate through the whole vector and then use if conditions for the data types, or is there another way? I have posted an example of my read file code and file to give you a clearer understanding of what I mean.

Thanks,

// Basic read file code

    fstream file("filepath.txt", ios::in); // reads file
    string line;  // temp storage of lines in file
    vector<string> lines; // creates for permanent storage  
    while (getline(file, line))
    {
        lines.push_back(line);
    };  // pushes each line to back of vector until file end.

file example - each string is a question with the line below being the answer as an int. 88 lines in total.

1, string"
2, int
3,"string"
4, int
5,"string"
6, int

CodePudding user response：

You should create two vectors and push_back data alternately, hope this help :)

CodePudding user response：

You got almost there, the code in your example is good. Just missing a second step:

    // storage
    std::vector<int> integers;
    std::vector<std::string> strings;

    // open file and iterate
    std::ifstream file( "filepath.txt" );
    while ( file ) {

        // read one line
        std::string line;
        std::getline(file, line, '\n');

        // create stream for fields
        std::istringstream ils( line );
        std::string token;

        // read integer (I like to parse it and convert separated)
        if ( !std::getline(ils, token, ',') ) continue;
        int ivalue;
        try { 
            ivalue = std::stoi( token );
        } catch (...) {
            continue;
        }
        integers.push_back(  ivalue );

        // Read string
        if ( !std::getline( ils, token, ',' )) continue;
        strings.push_back( token );
    }

Godbolt: https://godbolt.org/z/4aMv6MW4K

BTW the using std; practice can bite you in the future. Try to keep the std:: prefix in the code, it's safer.