Table of Contents
In this tutorial, we will learn how to take input from user and display the output to user with the help of examples.
C++ Output
In C++, we use cout
to sent formatted output to standard output devices, such as the screen . We use the cout
object along with the <<
( insertion operator ) for displaying output. The insertion operator << also called the put to
operator directs the information on its right to the object on its left.
The cout
object can be used to display individual characters, strings and even numbers. It is predefined object that refers to the standard output stream. The cout
object, whose properties are defined in <iostream> represents that stream.
#include <iostream>
using namespace std;
int main() {
// prints the string enclosed in double quotes
cout << "How to print output on output deveices.";
return 0;
}
Output
How to print output on output deveices.
How does this program work?
- In first line of program we have included the
iostream
header file that allows us to display output. - Namespaces are used to organize code into logical groups and to prevent name collisions that can occur especially when your code base includes multiple libraries .The
cout
object is defined inside thestd
namespace. To use thestd
namespace, we used theusing namespace std;
statement. - Every C++ program starts with the
main()
function, that’s why it’s called as entry point of any program in C++. cout
is an object that prints the string inside quotation marks" "
as it is. It goes along with the<<
operator.return 0;
is the “exit status” of themain()
function. The program ends with this statement, however, this statement is not mandatory.
#include <iostream>
int main() {
// prints the string enclosed in double quotes
std::cout << "How to print output on output deveices.";
return 0;
}
Note: If we don’t include the
using namespace std;
statement, we need to usestd::cout
instead ofcout
.
C++ Input
In C++,we use cin
takes formatted input from standard input devices such as the keyboard. We use the cin
object along with the >>
(extraction operator) for taking input. The extraction operator >> also called the get from
operator directs the information on its left to the object on its right.
#include <iostream>
using namespace std;
int main() {
int num;
cout<<"Enter a number of our choice:";
cin>>num;
cout<<"You have entered:"<<num;
return 0;
}
Output
Enter a number of our choice:34
You have entered:34
Cascading Of Input/Output Operator
Insertion and extraction, more the one time in single statement is known as Cascading of Input/Ouput Operator.
#include <iostream>
using namespace std;
int main() {
int numOne, numTwo;
cout << "Enter two integer numbers: ";
cin >> numOne >> numTwo; //cascading of extration operator
cout << "Number One is : " << numOne << endl; //cascading of insertion operator
cout << "Number Two is :" << numTwo;
cout << "Average of two given number is :"<< (numOne+numTwo)/2;
return 0;
}
Output
Enter two integer numbers:28
24
Number One is :28
Number Two is :24
Average of two given number is : 26