How to Receive Input From a User in C++

In this article, we show how to receive input from a user in C++.

Not every program in C++ is just you as a programmer outputting data to a screen.

Many times, we'll want to receive input from a user.

So how do we receive input from a user in C++?

We use the cin function.

Just as we output data to a user using the cout function, we receive input from a user using the cin function.

However, unlike a cout function, which uses <<, the cin function has the symbols going to the opposite side, >>.

We will show 2 programs of us getting input from a user, first a string and then a number.

Receiving a String From a User

A string is a group of characters joined together that can be comprised of letters, numbers, and other combination of characters.

A string can be any characters such as a color like "blue", "orange", "brown", etc.

In the program below we will ask the user for his or her favorite color.

#include <iostream> #include <string> using namespace std; int main() { string favoritecolor; cout << "What is your favorite color? "; cin >> favoritecolor; cout << "Your favorite color is " << favoritecolor << endl; return 0; }

So in order to output data to a user or get input data from a user, you need the iostream library. This is obtained through the line, #include

In order to use strings in C++, you must include the string library. This is obtained through the line, #include

We then use the line, using namespace std;, so that we don't have to use std:: throughout the code.

We then have our main() function, which is where our program begins.

We create a string, favoritecolor.

We then ask the user what is his/her favorite color.

With the line, cin >> favoritecolor;, we are able to save the input that the user enters into the string variable, favorite color.

We then output the favoritecolor variable that has saved the user's favorite color.

Receiving a Number From a User

We now show how to receive a number (in this case, specifically an integer) from a user.

This is shown below.

#include <iostream> using namespace std; int main() { int favoritenumber; cout << "What is your favorite number? "; cin >> favoritenumber; cout << "Your favorite number is " << favoritenumber << endl; return 0; }

So this program is very similar to the first with the exception that the user we are looking for now is an integer, not a string.

Therefore, we declare a int, favoritenumber.

We then save this number that the user enters into the int variable, favoritenumber.

And this is how to receive input from a user in C++.

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