Is it possible to input multiple values in a single line using `std::cin`?

Question

Ryan McCombe · Accepted Answer

Yes, it's absolutely possible to input multiple values in a single line using std::cin.

This is actually one of the convenient features of std::cin - it can handle multiple inputs separated by whitespace (spaces, tabs, or newlines). Let's explore how to do this effectively:

Basic Multiple Input

Here's a simple example of reading multiple values from a single line:

1#include <iostream>
2#include <string>
3
4int main(){
5  int age;
6  std::string name;
7  double height;
8
9  std::cout <<
10    "Enter your name, age, and height: ";
11  std::cin >> name >> age >> height; 
12
13  std::cout << "Name: " << name << "\n";
14  std::cout << "Age: " << age << "\n";
15  std::cout << "Height: " << height <<
16    " meters\n";
17}

In this example, the user can enter something like "John 25 1.75" on a single line, and std::cin will distribute these values to the appropriate variables.

1Enter your name, age, and height: John 25 1.75
2Name: John
3Age: 25
4Height: 1.75 meters

Handling Input with Spaces

The basic approach works well for simple types, but what if we want to input a full name with spaces? We can combine std::cin with std::getline():

1#include <iostream>
2#include <string>
3#include <sstream>
4
5int main(){
6  std::string fullName;
7  int age;
8  double height;
9
10  std::cout <<
11    "Enter your full name, age, and height: ";
12  std::getline(std::cin, fullName, ','); 
13  std::cin >> age >> height;
14
15  std::cout << "Full Name: " << fullName <<
16    "\n";
17  std::cout << "Age: " << age << "\n";
18  std::cout << "Height: " << height <<
19    " meters\n";
20}

Here, we use std::getline() to read the full name up to a comma, then use std::cin for the remaining values. The user would input something like "John Doe, 25 1.75".

1Enter your full name, age, and height: John Doe, 25 1.75
2Full Name: John Doe
3Age: 25
4Height: 1.75 meters

Using a String Stream

For more complex input parsing, we can use a string stream:

1#include <iostream>
2#include <string>
3#include <sstream>
4
5int main(){
6  std::string input;
7  std::string name;
8  int age;
9  double height;
10
11  std::cout <<
12    "Enter name, age, and height (separated by "
13    "commas): ";
14  std::getline(std::cin, input);
15
16  std::istringstream iss(input); 
17  std::getline(iss, name, ',');
18  iss >> age;
19  iss.ignore(); // Ignore the comma
20  iss >> height;
21
22  std::cout << "Name: " << name << "\n";
23  std::cout << "Age: " << age << "\n";
24  std::cout << "Height: " << height <<
25    " meters\n";
26}

1Enter name, age, and height (separated by commas): John,25,1.75
2Name: John
3Age: 25
4Height: 1.75 meters

This approach gives you more control over how the input is split and parsed. It's particularly useful when dealing with more complex input formats or when you need to do additional validation.

Remember, when working with multiple inputs, always consider potential input errors and implement appropriate error handling to make your program robust.

User Input in the Terminal

Multiple Inputs on a Single Line in C++

Basic Multiple Input

Handling Input with Spaces

Using a String Stream

User Input in the Terminal

Intro to C++ Programming

Questions & Answers