How to limit character input "cin" to get just one string - c++

Question

I was writing this code for training, and I'm in a problem where if my user write his name followed by a space and something else, the program will mess up my flow. So it's easier if you try the little program and when it ask for name, put like "Robert Red". The problem occurs just when you put something else after the space, if you input just "Robert" all goes good.
This is the code:
// Description: This is a simple replica of the Japanese game Rock, Paper and
// Scissors.
// Author: Ernesto Campese
// Last Update: 11/04/2018
// Version: 0.0.1
#include "std_lib_facilities.h"
int main() {
string username = "";
char userinput;
int rounds = 0;
int wins = 0;
int draws = 0;
int loses = 0;
int user_secret = 0;
vector<string> options = {"Paper", "Scissors", "Rock"};
cout << "Enter your name: ";
cin >> username;
cout << "Welcome " << username << ", this is the game of Rock, Paper and Scissors.\n";
cout << username << " how many rounds you want to do? ";
cin >> rounds;
if (rounds <= 0) {
cout << "You need to play at least one round!\n";
rounds++;
}
cout << "The game is based on " << rounds << " rounds, you versus the CPU.\n";
cout << "Are you ready? (y/n): ";
cin >> userinput;
if (userinput != 'y') {
cout << "\nThank you.\nProgram Terminated by " << username;
return 0;
}
for(int i = 1; i <= rounds; i++) {
// Title of the rounds
if (i == 1) {
cout << "\nLet's start the first round!\n";
} else {
cout << "Round n. " << i << " begins!\n";
}
// USER makes a move
cout << "Which is your move? (r,p,s): ";
cin >> userinput;
cout << '\n' << username << " says... ";
switch (userinput) {
case 'r':
cout << "Rock\n";
user_secret = 2;
break;
case 'p':
cout << "Paper\n";
user_secret = 0;
break;
case 's':
cout << "Scissors\n";
user_secret = 1;
break;
default:
cout << "something weird...\n";
break;
}
// CPU makes a move
int cpu_secret = rand() % 3;
cout << "CPU says... " << options[cpu_secret] << "!\n";
// The program calculates the result.
if (user_secret == cpu_secret) {
draws++;
cout << username << " and the CPU draws!\n\n";
} else if (user_secret == 0 && cpu_secret == 2) {
wins++;
cout << username << " wins!\n\n";
} else if (user_secret == 1 && cpu_secret == 0) {
wins++;
cout << username << " wins!\n\n";
} else if (user_secret == 2 && cpu_secret == 1) {
wins++;
cout << username << " wins!\n\n";
} else {
loses++;
cout << username << " lose!\n\n";
}
}
cout << "\n\nBattle End!\n";
if (wins > loses) {
cout << username << " won the battle!\n";
} else if (loses > wins) {
cout << username << " lost the battle!\n";
} else {
cout << username << " draws the battle!\n";
}
cout << "Thank you " << username << "!\n";
}
You can try it here: Try me
Thank you!

Answer 1

operator>> stops reading input when it finds a whitespace character.
Use std::getline() to read user input with spaces.
Example using your code:
cout << "Enter your name: ";
getline(cin, username);

Answer 2

If you want the user to be able to type in a name that has spaces in it, use std::getline() instead of operator>>:
getline(cin, username);
Otherwise, if you want the user to enter only 1 word for the name, and you want to ignore anything else the user may enter, use std::cin.ignore():
#include <limits>
...
cin >> username;
cin.ignore(numeric_limits<streamsize>::max(), '\n');
Alternatively, you can use std::getline() to read a line, and then use std::istringstream with operator>> to extract the 1st word of the line:
#include <sstream>
...
string line;
getline(cin, line);
istringstream(line) >> username;