cin input not being accepted in while loop [closed] - c++

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Hi I'm trying to use a cin input but on my second while loop, the inputs are not running though correctly. How would I go about this?
Here's what I have:
#include <iostream>
#include <string>
#include <fstream>
#include <iomanip>
using std::endl;
using std::cout;
using std::cin;
using namespace std;
int a, A;
int main() {
int choice, num;
cout << "State Search" << endl;
cout << "" << endl;
cout << "1. Enter the first letter of your desired state" << endl;
cout << "2. Press 2 to Quit" << endl;
cout << "" << endl;
bool done = false;
while(!done) {
//user inputs desired choice
cin >> choice;
if(choice == a || choice == A)
{
cout << "Which State? (enter a number)" << endl;
cout << "1. Alabama" << endl;
cout << "2. Alaska" << endl;
cout << "3. Arizona" << endl;
cout << "" << endl;
while (!(cin >> num))
{
if(num == 1)
{
cout << "test output 1" << endl;
}
else if (num == 2)
{
cout << "test output 2" << endl;
}
else if (num == 3)
{
cout << "test output 3" << endl;
}
} break;
} break;
}
return 0;
}
Once the user chooses one of the above states using a number I want to display the chosen output.

Answer 1

Here is a cleaned up version of what you are trying to do with some inline comment where you were going wrong.
// You only need to include iostream in your example program
// Only include what you need
#include <iostream>
#include <limits>
// You do not need to include all of the std namespace in the local scope
// if you are using the things you want.
using std::endl;
using std::cout;
using std::cin;
using std::streamsize;
int main()
{
cout << "State Search\n\n";
cout << "1. Enter the first letter of your desired state\n";
cout << "2. Press 2 to Quit\n" << endl;
// Removed all the while(!done) / break; as it is just noise in the current iteration of your program.
// if you use an int for the choice variable, you will actually try to parse the input
// as an integer and return 0 if the user inputs 'a'
// you need to use a char for what you want to do
char choice;
cin >> choice;
// Also your a and A int value do not make sense as they are init to 0
// (global initialization), I guess what you want to do is compare to the char 'a' or 'A'. You could also transform the input to lowercase and compare only to 'a'.
if (choice == 'a' || choice == 'A')
{
// Use \n not std::endl as it will flush the output buffer
// all the time. std::endl is a false friend, use it only
// when you want to present your text to the user.
cout << "Which State? (enter a number)\n";
cout << "1. Alabama\n";
cout << "2. Alaska\n";
cout << "3. Arizona\n" << endl;
// We want to wait until we get a correct input and _then_
// do something with our input.
int num;
while (!(cin >> num))
{
// You might want to say something to your user if he doesn't input a correct number here.
// This will succeed if the user inputs 4, so you might also want to handle that case differently and ask the user to retry too in that case.
// The stream is now in error, you need to reset the state of the stream by clearing the error and emptying the buffer.
cin.clear();
cin.ignore(std::numeric_limits<streamsize>::max(), '\n');
}
// Just showing another way of doing the if / else if dance in C/C++.
switch(num)
{
case 1: cout << "You chose Alabama" << endl; break;
case 2: cout << "You chose Alaska" << endl; break;
case 3: cout << "You chose Arizona" << endl; break;
default: cout << "I do not recognize the State" << endl; break;
}
}
// if we didn't receive 'a' or 'A' we just quit the program.
return 0;
}