Simple File I/O Example

//Reads three numbers from the file infile.dat,

//sums the numbers, and writes the sum to the

//file outfile.dat

#include <fstream>

int main( )

{

using namespace std;

ifstream in_stream;

ofstream out_stream;

in_stream.open("infile.dat");

out_stream.open("outfile.dat");

int first, second, third;

in_stream >> first >> second >> third;

out_stream << "The sum of the first 3\n"

<< "numbers in infile.dat\n"

<< "is " << (first + second + third)

<< endl;

in_stream.close( );

out_stream.close( );

return 0;

}

1

2

3

4

The sum of the first 3

numbers in infile.dat

is 6

infile.dat

outfile.dat

Note that there is no output to the screen

and no input from the keyboard

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