How to write std::string to file?
You're currently writing the binary data in the string
-object to your file. This binary data will probably only consist of a pointer to the actual data, and an integer representing the length of the string.
If you want to write to a text file, the best way to do this would probably be with an ofstream
, an "out-file-stream". It behaves exactly like std::cout
, but the output is written to a file.
The following example reads one string from stdin, and then writes this string to the file output.txt
.
#include <fstream>
#include <string>
#include <iostream>
int main()
{
std::string input;
std::cin >> input;
std::ofstream out("output.txt");
out << input;
out.close();
return 0;
}
Note that out.close()
isn't strictly neccessary here: the deconstructor of ofstream
can handle this for us as soon as out
goes out of scope.
For more information, see the C++-reference: http://cplusplus.com/reference/fstream/ofstream/ofstream/
Now if you need to write to a file in binary form, you should do this using the actual data in the string. The easiest way to acquire this data would be using string::c_str()
. So you could use:
write.write( studentPassword.c_str(), sizeof(char)*studentPassword.size() );
Assuming you're using a std::ofstream
to write to file, the following snippet will write a std::string
to file in human readable form:
std::ofstream file("filename");
std::string my_string = "Hello text in file\n";
file << my_string;