File IO of Numeric and String Data
Understand the file handling of Numeric and String data in C++.
We'll cover the following...
Challenge
Write a program to write numeric and string data into a file called SAMPLE.TXT. Read the same file back and display the contents read on the screen.
Sample run
root@educative:/usr/local/educative# g++ main.cpp
root@educative:/usr/local/educative# ./a.out
Z
25
473.14
Hyperbole!
root@educative:/usr/local/educative# cat SAMPLE.TXT
Z
25
473.14
Hyperbole!
Coding exercise
Your job is to write the code for writing and reading to the file in the main( ) function.
// File IO of numeric and string data
#include <fstream>
#include <iostream>
int main( )
{
char ch = 'Z' ;
int i = 25 ;
float a = 473.14f ;
char str[ ] = "Hyperbole!" ;
// Your code goes here
// send data to screen
std :: cout << ch << std :: endl ;
std :: cout << i << std :: endl ;
std :: cout << a << std :: endl ;
std :: cout << str << std :: endl ;
return 0 ;
}Coding solution
The following code widget has the solution for the challenge explained above.
// File IO of numeric and string data
#include <fstream>
#include <iostream>
int main( )
{
char ch = 'Z' ;
int i = 25 ;
float a = 473.14f ;
char str[ ] = "Hyperbole!" ;
// create file for output
std :: ofstream outfile ( "SAMPLE.TXT" ) ;
// send data to file
outfile << ch << std :: endl ;
outfile << i << std :: endl ;
outfile << a << std :: endl ;
outfile << str << std :: endl ;
outfile.close( ) ;
std :: ifstream infile ( "SAMPLE.TXT" ) ;
// read data from file
infile >> ch >> i >> a >> str ;
// send data to screen
std :: cout << ch << std :: endl ;
std :: cout << i << std :: endl ;
std :: cout << a << std :: endl ;
std :: cout << str << std :: endl ;
return 0 ;
}Explanation
The contents of the file are displayed on the console using the cat command followed by the filename, like this:
cat SAMPLE.TXT
To begin with, we have defined an object called outfile, of type ofstream ...