Outputing Results to a File

Heya folks I need help. This is probably stupidly dumb and simple but i need it non the less. I'm currently doing an assignemt for a temperature converter. It goes like so:

Input Number
Convert to (lets just say err Fahrenheit)
Output result Onscreen with cout

What i'd like to do to expand my program is to also make my program write this result to a .txt file. Kind of like a log file. Can anyone help? This is very urgent to me

>What i'd like to do to expand my program is to also make my program write this result to a .txt file.

Code:

#include <fstream>
using namespace std;
.
.
char filename[] = "temp_log.txt";
ofstream out(filename);
out << Fahrenheit << endl;

Don't you need something else? Like whatever the command is to make it append the file and not erase it every time and then write it.

Originally Posted by swoopy

>What i'd like to do to expand my program is to also make my program write this result to a .txt file.

Code:

#include <fstream>
using namespace std;
.
.
char filename[] = "temp_log.txt";
ofstream out(filename);
out << Fahrenheit << endl;

Ok the namespace std? Is that what i typicalyl use as main() ?
and out << Fahrenheit is cout << Fahrenheit ?

and Thanks for the very quick reply

Originally Posted by cerin

Don't you need something else? Like whatever the command is to make it append the file and not erase it every time and then write it.

Oh yea that'd be most imprtant. I'd like it to log each result one after another kinda like:

212 Fahrenheit
123 Celcius
342 Absolute


That's how my results are formatted. I used a string copy, so when the user chooses which they want to convert to the program writes the string as the temperature type it's converting to.

>make it append the file and not erase it every time and then write it.
Well, to append use:

Code:

ofstream out(filename, ios::app);

>Ok the namespace std? Is that what i typicalyl use as main() ?
A short program would look like this, unless you want to append std:: to anything from the C++ standary library. Maybe you've got an old compiler?

Code:

#include <fstream>
using namespace std;

int main()
{
   char filename[] = "temp_log.txt";
   ofstream out(filename, ios::app);
   out << Fahrenheit << endl;
}

>out << Fahrenheit is cout << Fahrenheit ?
cout << Fahrenheit; // Writes to the console (Console Out)
out << Fahrenheit; // Writes to a file in this example

Ahh great Thanks Snoopy & Cerin. I'll go try that right now *Fingers Crossed*

Thanks guys it's worked! Thanks so much It's now appending which is great

It looks like this so far:

251.60012FF10 - Fahrenheit

I only want it to show 251.6. Sounded simple enough to fix so by altering the declared "Result" to "Result[4]" but it gives me apile of errors. X_X Yikes. Anyone have any ideas?

>I only want it to show 251.6.
If your temperature is a double or float, you can do:

Code:

out << fixed << setprecision(1) << Fahrenheit << endl;

Make sure to:

Code:

#include <iomanip>

at the top.

out << fixed << setprecision(1) << Result << out << " - " << Temp_Type << endl;

That's my out. Unfourtunatly it's still giving
"212.00012FF10 - Fahrenheit"

Also it's a Float.

Code:

out << fixed << setprecision(1) << Result << out << " - " << Temp_Type << endl;

Get rid of that out in red above. That extra out is causing the bad data in your file, it is likely that the value displayed is the address of the out stream object.

Ah Thanks again