How to Handle File I/O in C++

Instructions

• 1

  “fstream” provides two different functions for file inputs and file outputs. The function which is used to get input from a file is called ifstream, and for the outputs we use ofstream. Both of these functions provide file open and close functions as well.
• 2

  To open a file for an input use following syntax:

  
  

  ifstream filexyz;

  
  

  Or alternatively if you know the name of the file use following:

  
  

  ifstream filexyz  (name_of_file);

  
  

  To read or write any file you have to open it first, for example if you want to open filexyz for input then use following:

  
  

  filexyz.open();

  
  

  This will open the file for inputs. Once you have done with file operations, you now close the file by using:

  
  

  filexyz.close();

  
  

  Same is the case with output wp-content/uploads.
• 3

  Once you are done with creation of wp-content/uploads, you can simply replace cin with file you created and cout with the output file you created for the input and output purpose.
• 4

  To demonstrate file I/O more effectively, consider following example in which will simply output a string to a file and will also read a string from a file.

  
  

  Example:

  
  
  # include
  # include
  using namespace std;
  int main( ){
  char   our_str[15]; // create a sequence of characters (a string) with length 15
  ofstream fout (“temporary.txt”); //create a temporary.txt file for outputs.
  fout.open();
  fout<<”these lines will be copied to temporary.txt” temporary.txt
  fout.close(); //close temporary.txt
  ifstream fin(temporary.txt); //open the file temporary.txt to take input from this file
  fin.open();
  ifstream>> our_str; //this will copy a string from temporary.txt to our_str
  cout<< our_str//this will show us what is copied from the file to our_str.
  fin.close(); //close the file
  return 0;
  }
  
  
  
  

  Implement the above example in your compiler and try to evaluate the output.