How to create ofstream file with name of variable?

问题:

char NAME[256];
cin.getline (NAME,256);
ofstream fout("NAME.txt"); //NAME???????

What i need to do to create file with NAME name?

回答1:

You could try:

#include <string>
#include <iostream>
#include <fstream>

int main() {
    // use a dynamic sized buffer, like std::string
    std::string filename;
    std::getline(std::cin, filename);
    // open file, 
    // and define the openmode to output and truncate file if it exists before
    std::ofstream fout(filename.c_str(), std::ios::out | std::ios::trunc);
    // try to write
    if (fout) fout << "Hello World!\n";
    else std::cout << "failed to open file\n";
}

Some useful references:

• http://en.cppreference.com/w/cpp/string/basic_string
• http://en.cppreference.com/w/cpp/string/basic_string/getline
• http://en.cppreference.com/w/cpp/io/basic_ofstream/basic_ofstream
• http://en.cppreference.com/w/cpp/io/basic_filebuf/open
• http://en.cppreference.com/w/cpp/io/ios_base/openmode

回答2:

Like this:

#include <string>
#include <fstream>

std::string filename;
std::getline(std::cin, filename);
std::ofstream fout(filename);

In older versions of C++ the last line needs to be:

std::ofstream fout(filename.c_str());

回答3:

You can try this.

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main()
{
    string fileName;
    cout << "Give a name to your file: ";
    cin >> fileName;
    fileName += ".txt"; // important to create .txt file.
    ofstream createFile;
    createFile.open(fileName.c_str(), ios::app);
    createFile << "This will give you a new file with a name that user input." << endl;
    return 0;
}