How to validate user input as an integer when using cin

Question

I am working error handling and validation of a code write now. I have searched Sololearn and other places like StackOverflow and found some stuff, but nothing that has worked yet. If there is something out there that I wasn't able to find that answers my question, please feel free to post the link! Here is some code I was using to test a function that receives and validate user input (I was testing it just using the "Menu" option so far). The context of the function is a plinko simulator. Here is the test code:

#include <iostream>
#include <climits>
using namespace std;

const int MENU_OPTION = 4;

int GetInputNumber(string inputUse, int lowerBound = INT_MIN, int upperBound = INT_MAX) {
int inputNumber = 0;

do {
if (inputUse == "Menu") {
cout << "Enter your selection now: ";
cin >> inputNumber;
cout << inputNumber << endl;
if (!(inputNumber >= lowerBound && inputNumber <= upperBound)) {
cout << "Invalid selection. Enter " << MENU_OPTION << " to see options." << endl;
cout << endl;
cin.clear();
cin.ignore(1000, '\n');
}
}
else if (inputUse == "Choose Slot") {
cout << "Which slot do you want to drop the chip in (0-8)? ";
cin >> inputNumber;
cout << inputNumber << endl;
if (!(inputNumber >= lowerBound && inputNumber <= upperBound)) {
cout << "Invalid slot." << endl;
cout << endl;
}
}
else if (inputUse == "Chip Amount") {
cout << "How many chips do you want to drop (>0)? ";
cin >> inputNumber;
cout << inputNumber << endl;
if (!(inputNumber >= lowerBound && inputNumber <= upperBound)) {
cout << "Invalid number of chips." << endl;
cout << endl;
}
}
else {
cout << "GetInputNumber Error" << endl;
break;
}
if (!(cin >> inputNumber)) {
cout << "That was not an integer" << endl;
inputNumber = 1;
//cin.clear();
//cin.ignore(1000, '\n');
}
} while (!(inputNumber >= lowerBound && inputNumber <= upperBound));

return inputNumber;
}

//int main()

Answer 1

do {
std::cin.clear();
std::cin.ignore(512, '\n');
std::cin >> InputNumber;
} while (std::cin.fail());

Answer 2

Or better, try-catch blocks.

while (loop) {
try {
std::cin >> InputNumber;
if (std::cin.fail())
throw 0;
if (inputOutOfBound)
throw 1;
//... etc
// if no errors thrown,
loop = false;
// exit loop
}
catch (int err) {
std::cin.clear();
std::cin.ignore(512, '\n');
switch (err) {
// error messages here
}
}
}

Answer 3

int main() {
GetInputNumber("Menu");

return 0;
}

Answer 4

Hatsy Rei the missing puzzle piece was cin.fail(). Thanks!