Question

Write C++ code to open a document with the name Hello.txt, place the message "Hello, World!" in the document, and exit the document. Re open the file you closed, and read the message into a string variable. Exit out of the file.

Answer 1

Answer:

#include<iostream>

#include<fstream>

using namespace std;

int main()

{

ofstream out;

out.open("Hello.txt");

out << "Hello, World!"<< endl;

out.close();

ifstream in;

in.open("Hello.txt");

while(in.good()){

   string line;

   in >> line;

   cout << line << endl;

   

}

in.close();

return 0;

}

Explanation:

Step 1:

Add all your preprocessor files directive,  #include is known as the preprocessor  is used to load files needed to run the code.

#include<iostream>: it provides basic input and output services for C++ programs.

#include<fstream>:used to open a file for writing and reading

using namespace std; means you'll be using namespace std means that you are going to use classes or functions (if any) from "std" namespace

Step 2:

ofstream out; his  is  used  to  create  files  and   write data to the file

out.open("Hello.txt");  a new file "HELLO.txt" has been created

out << "Hello, World!"<< endl;  "Hello World!" has now been writen to the file

out.close(); The file is now closed

This second step opens a new file and writes hello world to the file then closes it.

Step 3:

ifstream in; ifstream in c++ is a stream class which stands for input file stream a  is used for reading data from file.

in.open("Hello.txt"); Reopens the file without recreating it. This is a very important step because if not done properly, you might discard the file you previously created and recreate it.

while(in.good()){

in.good() is true if the previous read operation succeeded without EOF being encountered

   string line; It declares a string variable line

   in >> line; reads the data into the line variable

   cout << line << endl; Prints out the line

reopens the file and read the message into a string variable "line".  prints out line then exits out of the file.