C++ Loop for String - c++

Question

I am struggling to create a loop for getting input from user. The input must push_back() each instance.
#include <iostream>
#include <array>
#include <cstring>
#include <vector>
#include <string>
#include <string.h>
using namespace std;
int main()
{
vector <string> bookQ = { "what","book","is","that","you","are","reading" };
for (int i = 0; i < bookQ.size(); i++) {
cout << bookQ[i] << ' ';
}
cout << endl;
string input;
int x = 0;
for (x != '1') { // require a loop to input string and end when user prompts
cout << "Enter 1 to stop" << endl; //
cin >> x; //
getline(cin, input); //
bookQ.push_back(input); //
} //
for (int i = 0; i < bookQ.size(); i++) {
cout << bookQ[i] << ' ';
}
cout << endl;
return 0;
}

Answer 1

Your for loop is missing the declaration and (iteration) expression parts:
for (declaration-or-expression; declaration-or-expression; expression)
so it should have looked like this:
for (;x != '1';) {
which is generally written as
while (x != '1') {
That would cause problems though since it would not stop directly when the user entered 1.
You are also comparing an int with a char ('1'), so in order to exit the loop, the user would have had to enter 49 (the ASCII value for 1), not 1.
You are also mixing formatted input (cin >> x) with unformatted input (getline). I suggest that you stick to one only.
Example:
while(cout << "Enter 1 to stop\n", getline(cin, input) && input != "1") {
bookQ.push_back(input);
}

Answer 2

Assuming you meant that input is a string, then you've made a few mistakes with types. First of all, you've used wrong type for variable x, you used int which is integer type, and the type string is required. Secondly, when comparing x with '1' you used single quotes, which define the type of variable as char, not string. To make 1 a string you should use double quotes, like so "1". Besides that, you have used for(condition), which is incorrect syntax. You should use while(condition). Also, when your loop iterates, the x variable is the input book name, and input variable is always an empty string, so I would suggest replace input with x everywhere. The working code is below.
P.S. I am not sure whether you want "1" to be in the final vector, so I haven't changed that
#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main() {
vector<string> bookQ = {"what", "book", "is", "that", "you", "are", "reading"};
for (int i = 0; i < bookQ.size(); i++) {
cout << bookQ[i] << ' ';
}
cout << endl;
string input;
string x;
while (x != "1") {
cout << "Enter 1 to stop" << endl;
cin >> x;
bookQ.push_back(x);
}
for (int i = 0; i < bookQ.size(); i++) {
cout << bookQ[i] << ' ';
}
cout << endl;
return 0;
}

Answer 3

simply check if input is 1 everytime the user enters somthing, and when it does = 1, simply break loop.
string x;
while (true) { // require a loop to input string and end when user prompts
cout << "Enter 1 to stop" << endl;
cin >> x;
if (x == "1"){
break;
}
getline(cin, x);
bookQ.push_back(x);
}
}

Answer 4

First, your for syntax is wrong. You want a while loop instead, or in this case a do..while loop would make more sense. Also, you are pushing the user's input into the vector before validating what the input actually is.
Second, x is an integer, but '1' is a character whose ASCII value is number 49. Your loop will never end, because != will always be true. Since you want the user to enter number 1 to stop the loop, you need to drop the quotes:
Third, what is the point of pre-populating bookQ? Just declare the bookQ without any initial data, and then cout the entire question as a normal string. This way, after the user is done entering input, the vector will contain only the user's input and nothing else.
Try something more like this:
#include <iostream>
#include <vector>
#include <string>
#include <iomanip>
using namespace std;
int main()
{
vector <string> bookQ;
string input;
cout << "what book is that you are reading" << endl;
do {
cout << "Enter a book, or 1 to stop" << endl;
getline(cin >> ws, input);
if (input == "1") break;
bookQ.push_back(input);
}
while (true);
for (size_t i = 0; i < bookQ.size(); ++i) {
cout << bookQ[i] << ' ';
}
cout << endl;
return 0;
}