In C++, programs can interact with users by receiving input from the keyboard. While cout
is used to display output, cin
allows the program to capture input using the extraction operator (>>
).
Reading User Input
To prompt a user to enter a value, use cin
along with a variable to store the input.
Example
C++
x
using namespace std;
int main() {
int engineCC;
cout << "Enter engine capacity (cc): "; // Asking for user input
cin >> engineCC; // Storing the input
cout << "Your engine capacity is: " << engineCC;
return 0;
}
Explanation:
cout
displays a message asking the user to enter a number.cin >> engineCC;
stores the user’s input in the variableengineCC
.- The value entered is then displayed using
cout
.
Understanding cout
and cin
cout
(pronounced “see-out”) → Displays information using the insertion operator (<<
).cin
(pronounced “see-in”) → Captures input using the extraction operator (>>
).
Creating a Simple Calculator
Let’s build a program that asks the user for two numbers, adds them, and displays the result.
Example
C++
using namespace std;
int main() {
int speedA, speedB;
int totalSpeed;
cout << "Enter first speed: ";
cin >> speedA;
cout << "Enter second speed: ";
cin >> speedB;
totalSpeed = speedA + speedB;
cout << "Total combined speed is: " << totalSpeed;
return 0;
}
Explanation:
- The user enters two values (
speedA
andspeedB
). - The program adds them and displays the result.