How to write std string to file

Question

I want to write a std  string variable I am accepting from the user to a file  I tried using the write   method and it writes to the file  But when I open the file I see boxes instead of the string    The string is only a variable length single word  Is std  string suitable for this or should I use a character array or something   ofstream write  std  string studentName  roll  studentPassword  filename    public   void studentRegister         cout lt  lt  Enter roll number  lt  lt endl      cin gt  gt roll      cout lt  lt  Enter your name  lt  lt endl      cin gt  gt studentName      cout lt  lt  Enter password  lt  lt endl      cin gt  gt studentPassword        filename   roll     txt       write open filename c str    ios  out   ios  binary        write put ch       write seekp 3  ios  beg        write write  char    amp studentPassword  sizeof std  string        write close

User · Answer

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  lt  lt  my string

User · Answer

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  lt fstream gt   include  lt string gt   include  lt iostream gt   int main         std  string input      std  cin  gt  gt  input      std  ofstream out  output txt        out  lt  lt  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

User · Answer

remove the ios  binary from your modes in your ofstream and use studentPassword c str   instead of  char    amp studentPassword in your write write

[c++] How to write std::string to file?

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