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Basic Input & Output using cin and cout

cout [console output] <<

cout<< is used to display message/ value of variable to the console output device.

cout is an object of ostream class, operator << is known as insertaion or put to operator. it sends the value to the output device.

Simple form of cout

cout << "Message to display";
cout << variable_name;

Cascading form of cout

cout << "Message to display"/variable_name << "Message to display"/variable_name << ... ;

Example

Consider the example

// Program to illustrate cout 
// Author : includehelp.com
// Date : 13-03-2012

#include <iostream>
using namespace std;

int main()
{
	char text[]="Hello Guys!";
	int  val=100;
	cout<<"welcome to includehelp.com \n";
	// Using cascading form of cout
	cout <<"text: "<<text <<", val: "<<val;
	
	return 0;
}

Output

welcome to includehelp.com
text: Hello Guys!, val: 100

• cout is a static object of ostream class.
• while << (insertion operator)/(put to operator) is an overloaded operator of it.
• you can also write cout.operator<<("includehelp.com"); instead of cout<<"includehelp.com";

cin [console input] >>

cin>> is used to take value of variable from input device (keyboard).

cin is an object of istream class, operator >> is known as extraction or get from operator. it extracts (takes) the value from keyboard.

Simple form of cin

cin >> variable_name1;
cin >> variable_name2;

Cascading form of cin

cin >> variable_name1 >> variable_name2 >> ...;

Example

Consider the example

/* Program to illustrate cin 
    Author : includehelp.com
    Date : 13-03-2012
*/

#include <iostream>
using namespace std;

int main()
{
    char name[30];
    int marks;

    cout << "Enter name: ";
    cin >> name;
    cout << "Enter marks: ";
    cin >> marks;

    cout << "Hello " << name << " , You got " << marks << " marks in exam.\n";

    return 0;
}

Output

Enter name: Mike
Enter marks: 97
Hello Mike , You got 97 marks in exam.

Consider the example - Using cascading form of cin

/*  Program to illustrate cin 
    Author : includehelp.com
    Date : 13-03-2012
*/

#include <iostream>
using namespace std;

int main()
{
    char name[30];
    int marks;

    cout << "Enter you name and marks : ";
    cin >> name >> marks;

    cout << "Hello " << name << " , You got " << marks << " marks in exam.\n";

    return 0;
}

Output

Enter you name and marks : Mike 97
Hello Mike , You got 97 marks in exam.

• cin is a static object of istream class.
• while >> (extraction operator)/(get from operator) is an overloaded operator of it.
• you can also write cin.operator>>(variable_name); instead of cin>>variable_name;