input validation c++ with menu - c++

Question

i have this menu like so.
int choice;
cout <<"1: Exit\n2: Print Mark\n3: Print Name"<<endl;
cin >> choice;
while (choice != 1 && choice != 2 && choice != 3)
{
cout << "Invalid Choice <<endl;
cout <<"1: Exit\n2: Print Mark\n3: Print Name"<<endl;
cin >> choice;
}
so that is what i have so far but when ever i input letters it terminates is there a easier way to test for invalid inputs.
i know there is something like cin.fail()
but not sure on how to implement it

Answer 1

This simple line skip when it's a bad input.
td::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); // ignore and skip bad input

Answer 2

okay you can structure your code like this
do {
if (choice ==1)
{
exit(1);
}else if (choice==2)
{
//code
}
}else if (choice==3)
{
//code
}
}else if (choice==4)
{
//code
}else{
cout <<"Please enter a correct option"<<endl;
cin.clear();
string choice;
cin>>choice;
}
}while(!cin.fail())
This works 100%

Answer 3

If it is possible for changing that int to char you can do like this.
Its easy this way.
char choice;
cout <<"1: Exit\n2: Print Mark\n3: Print Name"<<endl;
cin >> choice;
while (choice != '1' && choice != '2' && choice != '3')
{
cout << "Invalid Choice <<endl;
cout <<"1: Exit\n2: Print Mark\n3: Print Name"<<endl;
cin >> choice;
}
If you want to get the choice back as int, you can do
int choiceInt = choice - '0';

Answer 4

First take a string as input then try to cast it to int to see if it is valid. You can make it like this (if using c++11):
#include <iostream>
#include <cstring>
using namespace std;
int main() {
int choice = -1;
while (true) {
string input;
cout << "1: Exit\n2: Print Mark\n3: Print Name" << endl;
cin >> input;
try {
choice = stoi(input);
if (choice > 0 && choice < 4) {
break;
}
} catch (const std::exception& e) {
}
cout << "Invalid input" << endl;
}
cout << "Your valid choice: " << choice << endl;
}