Thread: Looping Variables and outputting to .txt

Well....

Code:

char prof>>x[50];

Making up random code isn't going to get you anywhere. Go back to the tutorials and figure out how to do what you're trying to do. I could guess as to your intentions, but that would just waste both of our time.

Code:

cin.getline ( prof>>x, 50, '\n' );

Leave the >> operator alone for things like this. It works for cin, cout, and a number of other places, but not here (unless you're trying something very, very weird).

As for getting a filename..... First just accept the full line with an extension. Make the user enter "bleh.txt". Then after the program works, then go back and change it to automatically add the .txt extension.

Lastly, welcome to cboard.

for saving to a file, i use this:

Code:

       char filen[32];
       ofstream savef;
	cout << "Please enter the filename: (no .txt): ";
	cin >> filen;
	strcat(filen, ".txt");
	cout << endl << filen << " will be saved in the same directory as the program." << endl << endl;
	savef.open(filen);
       if (savef.is_open()) {
                // if it opened the file successfully, then put the write commands in here, ie.
               savef << variablename; //note the << operator here, not the >>
               //etc.
        }
        else {
               cout << "Error." << endl; //if the file could not be opened
       }

a brief explanation:
char filen[32] initializes the variable, in this case a char array of 32. normally i would use a string (string varname) but ofstream only takes char arrays. then cin is used to get input from the user, by typing, cin >> [variablename]. strcat() is a function that appends something to something else. in this case we want it to append ".txt" to the filen variable (where the filename inputted is stored). then i just tell the user where the file will be saved, and try to open the file.

Code tags........ Code tags.......

BTW, you run the risk of overrunning your buffer with that method. You should be using C++ strings, not C strings, but if you do use C strings, you need to be vigilant with regard to overrunning buffers.

and why do you want to modify the variable names? use vector for storing multiple instanses of the same data...

Originally Posted by Blurr

Thanks for the help, and especially the explanation. Still can't find anything on including variables in other variable's names.

Not that this is useful, but for the record it is possible if the variables are #defined constants:

Code:

#define var 3 
#define constantNum(a) constNum##a
#include <ostream>
int main()
{
    int constantNum(1), constantNum(2), constantNum(3);
    cout << constantNum(var);
}

Most of the time an array, vector, or map would be more appropriate though.