C++文件输入和创建

     #include <fstream>
         //头文件

     ifstream inf;
     ofstream ouf;
     inf.open("zy4.txt", ios::out);
     if (!inf)
     {
         inf.close();
         ouf.open("zy4.txt");
         if (ouf)
             cout << "zy4.txt Created successfully!" << endl;
     }
     else
         cout << "The file is exited !\n";    

  　　//创建文件

     ofstream fout1("zy4.txt");
     if (!fout1.is_open())
     {
         cerr << "无法打开文件 " << "zy4.txt" << endl;
         exit();
     }
     fout1 << S << endl;
     fout1.close();
  　　//写入文件