User Input in C++

Read a name and age in C++ with cin. cin >> stops at the first space.

BeginnerBasic ProgramsExample 3 of 14

user-input.cpp

1#include <iostream>
2#include <string>
3using namespace std;
4
5int main() {
6    string name;
7    int age;
8    
9    cout << "Enter your name: ";
10    cin >> name;
11    
12    cout << "Enter your age: ";
13    cin >> age;
14    
15    cout << "Hello, " << name << "! You are " << age << " years old." << endl;
16    
17    return 0;
18}

Output

Enter your name: Alice
Enter your age: 25
Hello, Alice! You are 25 years old.

What's going on

This C++ program reads a name and an age with cin and prints them back. cin >> is the usual first input, and it has a sharp edge.

#include <iostream> and #include <string>

cout / cin from iostream. string name needs <string>.

string name;

int age;

Declared, not filled yet. Until cin writes them, treat them as junk.

cout << "Enter your name: ";

No endl on purpose, so the cursor stays on the same line as the prompt.

cin >> name;

Reads one word. A space stops it. Type Alice Smith and name is just Alice. Then age tries to parse Smith and the stream fails. getline(cin, name) keeps the surname.

cin >> age;

Wants a number. Type twenty and cin fails. Later prints look insane unless you check if (!(cin >> age)).

cout << "Hello, " << name << "! You are " << age << " years old." << endl;

Text and variables in one chain. Sample: Alice and 25 → Hello, Alice! You are 25 years old.

Mixing >> and getline later leaves a newline in the buffer. The next getline then reads an empty line. That's a common bug, not a broken keyboard.

Next useful step is math on those numbers — Sum of Two Numbers.

PreviousDisplay Your Name NextSum of Two Numbers