Question

HW_6c - Append data to existing data in a file.

1. Include the following in the main.cpp file.

1. Prompt the user to enter 3 more numbers, then read the numbers and write them to

            the results.txt file.

• Include code so that when the data is written to file, it is appended (added on to the

    end of the existing data).

1. Open the results.txt file and verify that the file was written successfully.

/* OUTPUT

Here are the numbers in the file:

3

4

5

Enter 3 more numbers:

6

7

8

The numbers have been written (appended) to results.txt.

Press any key to continue . . . */

Please make the code based on C++, and make a description for each code.

Answer 1

#include<iostream>
#include<fstream>
using namespace std;

/*main function*/
int main()
{  
   ofstream fout; // for writing to a file
   ifstream fin; // for reading from a file
   fin.open("results.txt"); // opening file
   // used append mode which is used to append data at the end of file
   fout.open("results.txt",ios::app);
   if(!fout && !fin){ // check if file not open
       cout<<"Error File not found!"<<endl;
       return 0;
   }
   int num; // to read number in variable
   cout<<"Here are the numbers in the file: \n";
   while(fin>>num){
       cout<<num<<endl; // print content of file
   }  
   cout<<"Enter 3 more numbers: "<<endl; // take input
   for(int i = 0; i < 3; i++){
       cin >> num; // taking input
       fout<<"\n"<<num; // writing to a file
   }
   cout<<"The numbers have been written (appended) to results.txt."<<endl;
   system("pause");
   return 0;
}

/* Screenshot of a code for indentation */

/* OUTPUT */

/* results.txt */