How to add a string into a vector in a switch case menu in C++
The task I have is to make a vector of strings, add strings to it, and delete strings from it. I am having trouble with adding strings, based on the book I am reading (Beginning C++ through game programming)
//gaming Queue
#include <iostream>
#include <vector>
#include <algorithm>
#include <ctime>
#include <cstdlib>
using namespace std;
int main()
{
int choice;
string input;
bool menu = true;
vector<string> favGames;
while (menu){
cout <<"Welcome to the favorite game queue please add your favorite games:\n";
cout <<"1-Add a favorite game.\n";
cout <<"2-List of your favorite games.\n";
cout <<"3-Remove a game.\n";
cin >> choice;
switch (choice)
{
case 1:
cout << "Please add a favorite game to the queue: \n";
string input;
cin >> input;
favGames.push_back(input);// Here is my problem it just jumps to case 2 and shows an error
break;
case 2:
cout << "Here is a list of your favorite games.\n";
break;
case 3:
cout << "No longer like a game which game should we remove?\n";
break;
default:
cout << "You made an illegal choice.\n";
}
}
return 0;
}
When compiling your code on https://www.onlinegdb.com/online_c++_compiler, it shows me those error:
main.cpp:34:18: error: jump to case label [-fpermissive]
case 2:
^
main.cpp:30:24: note: crosses initialization of 'std::string input'
string input;
as you can see the compiler tells you that you're skipping the initialization of string input. At the same time you are declaring input a second time.
By removing input inside the switch case, the program compiles and works as intended.
EDIT:
You can't enter more than one word using cin because cin extraction always considers spaces (whitespaces, tabs, new-line...) as terminating the value being extracted.
So you have to use getline. Same for when getting choice.
here is the full code:
#include "stdafx.h"
#include <vector>
#include <string>
#include <iostream>
#include <sstream>
using namespace std;
int main()
{
int choice;
string input;
bool menu = true;
vector<string> favGames;
while (menu) {
cout << "Welcome to the favorite game queue please add your favorite games:\n";
cout << "1-Add a favorite game.\n";
cout << "2-List of your favorite games.\n";
cout << "3-Remove a game.\n";
string choiceStr;
getline(cin, choiceStr);
stringstream(choiceStr) >> choice;
switch (choice)
{
case 1:
cout << "Please add a favorite game to the queue: \n";
getline(cin, input);
favGames.push_back(input);
break;
case 2:
cout << "Here is a list of your favorite games.\n";
break;
case 3:
cout << "No longer like a game which game should we remove?\n";
break;
default:
cout << "You made an illegal choice.\n";
}
}
return 0;
}
The reason why it enters infinite loop:
The cin >> input can only work when you enter only one word. If you enter several words, the cin >> input will catch the first one then the cin >> choice will catch the next one. If the input catch by cin >> choice is not an int, the cin will fail which makes you an infinite loop in this case.
It is explained here http://www.cplusplus.com/doc/tutorial/basic_io/.