ExternCode

C++ comes with libraries for performing input and output operation. In C++ I/O performed in the form of sequence of bytes known as streams.

In C++ I/O occurs in form of streams, bytes flow from a device like a keyboard, a disk drive, or a network connection etc. to main memory, this is called input operation and bytes flow from main memory to a device like a display screen, a printer, a disk drive, or a network connection, etc., this is called output operation

Header files in C++ for Input – Output operation are:

<iostream>

The cin, cout, cerr and clog objects defined in iostream class, which correspond to the standard input/output stream, the un-buffered standard error stream and the buffered standard error stream, respectively.

<iomanip>

The methods declared are used for manipulating streams. This file contains definitions of setw, setprecision etc.

In C++ articles, these two keywords cout and cin  are used very often for inputs and outputs. For using cin and cout we must include the header file iostream in our program.

In this article we will mainly discuss about the objects defined in the header file iostream like cin and cout.

The Standard Input Stream (cin)

The Object cin is an instance of istream class. cin tied to the standard input devices like keyboard. The cin object is used with the stream extraction operator (<<).

#include <iostream>

using namespace std;

int main() {

  char name[50];

  cout << "Please enter platform name: ";

  cin >> name;

  cout << "Your name is: " << name << endl;

 return 0;

}

Output:

Please enter platform name: Medium!

Medium!

The advantage of C++ is we need not to worry about the data type of input from user, this work is done by C++ compiler automatically.

Similarly, more than one input can be given as given below.

cin>> variable1 >> variable2;

The Standard Output Stream (cout)

The object cout is an instance of ostream class. cout tied to the standard output devices like monitor which displays the output. The cout object is used with the stream insertion operator (<<).

#include <iostream>

using namespace std;

int main() {

char str[] = "Hello World!";

cout <<str<<endl;

 return 0;

}

Output:

Hello World!

Numbers and characters are stored in variables. Variables are processed by the program. Variables can be modified by expressions. Variables can be assigned a value using the keyboard.

The following information components are associated with a variable:

The name symbolizes the location of the value.

>>The value stored in the memory location. >>The address that exactly describes the position in the memory of the computer. >>An address is always a hexadecimal value for a memory location in the computer's memory. >>The data type that specifies the format for the value to store.

A data type is the internal assignment of the bit sequence of a value.