#include
#include
using namespace std;
void test_write_read_cin_getline()
{
char data[100];
// open a file in write mode.
ofstream outfile;
outfile.open("TheMisteryMethod.txt");
cout << "Writing to the file" << endl;
cout << "Enter your name: ";
cin.getline(data, 100);
// write inputted data into the file.
outfile << data << endl;
cout << "Enter your age: ";
cin >> data;
cin.ignore();
// again write inputted data into the file.
outfile << data << endl;
// close the opened file.
outfile.close();
// open a file in read mode.
ifstream infile;
infile.open("TheMisteryMethod.txt");
cout << "Reading from the file" << endl;
infile >> data;
// write the data at the screen.
cout << data << endl;
// again read the data from the file and display it.
infile >> data;
cout << data << endl;
// close the opened file.
infile.close();
}
void test_write()
{
ofstream myfile;
myfile.open ("TheMisteryMethod.txt",ios::app);
if(myfile.is_open())
{
myfile <<
"\nTo recap, the three main objectives in the Mystery Method are: \n\
To attract a woman \n\
To establish comfort, trust, and connection \n\
To structure the opportunity to be seduced \n";
myfile.close();
}
else
cout<<"打开文件失败！\n";

}
void test_write_read_getline()
{
string str;

//Creates an instance of ofstream, and opens TheMisteryMethod.txt
ofstream a_file ( "TheMisteryMethod.txt",ios::app );//追加方式
// Outputs to TheMisteryMethod.txt through a_file
if(a_file.is_open())
{
a_file<<"A woman's number-one emotional priority is safety and security.";
// Close the file stream explicitly
a_file.close();
}
else
cout << "Unable to open file\n";

//Opens for reading the file 追加方式
ifstream b_file ( "TheMisteryMethod.txt",ios::app );
//Reads one string from the file
b_file>> str; //只显示to 表示遇到空格停止接收字符
cout<< str <<"\n";
getline(b_file,str,'\0');//输出缓冲区剩余的字符
cout<< str <<"\n";
cin.get(); // wait for a keypress
// b_file is closed implicitly here
}
void GetSizeOfFile(string filename)
{
long begin,end;
ifstream myfile (filename.c_str());//必须转换为c风格字符串
begin = myfile.tellg();
myfile.seekg (0, ios::end);
end = myfile.tellg();
myfile.close();
cout < }
int main ()
{
test_write_read_cin_getline();
test_write();
test_write_read_getline();
string file("TheMisteryMethod.txt");
GetSizeOfFile(file);
return 0;
}
/**********************************
程序运行结果如下：
Writing to the file
Enter your name: wangshihui
Enter your age: 22
Reading from the file
wangshihui
22
wangshihui

22

To recap, the three main objectives in the Mystery Method are:
To attract a woman
To establish comfort, trust, and connection
To structure the opportunity to be seduced
A woman's number-one emotional priority is safety and security.

TheMisteryMethod.txt size is: 294 bytes.

Process returned 0 (0x0) execution time : 13.100 s
Press any key to continue.

***********************************/

C++ has two basic classes to handle files, ifstream and ofstream. To use them, include the header file fstream. Ifstream handles file input (reading from files), and ofstream handles file output (writing to files). The way to declare an instance of the ifstream or ofstream class is:

ifstream a_file;
or