C++ Recursive Function Infinite Loop - c++

Question

I have a function which takes an int value from another function. When I type a wrong int value it works as intended (calls the same function recursively & lets me enter a new number) but when I type anything other than an int (a, %, etc) it calls the function recursively but gets stuck in an infinite loop. Any help/insight would be great as I am in the learning stages of C++ Programming.
Here is my Full code snippet (49 Lines)
To summarize what I am asking is how would I properly go about displaying an error and returning back to the Main Menu without triggering the infinite loop when a non-int value is given.
int MainMenu();
void MainMenuSelection(int x);
int main()
{
MainMenuSelection(MainMenu());
return 0;
}
int MainMenu() {
int selection;
std::cout << "C++ Tutorials Main Menu\n";
std::cout << "----------------------------------------------\n";
std::cout << "1 - Chapter #1\n";
std::cout << "2 - Chapter #2\n";
std::cout << "3 - Chapter #3\n";
std::cout << "----------------------------------------------\n";
std::cout << "Please enter a cooresponding value: ";
std::cin >> selection;
if (std::cin.fail()) {
std::cout << "Input must be an integer";
}
else {
return selection;
}
}
void MainMenuSelection(int x) {
if (x == 1) {
std::cout << "\nChapter #1 is unavailable.\n";
std::cout << std::string(22, '\n');
MainMenuSelection(MainMenu());
}
else if (x == 2) {
std::cout << std::string(2, '\n');
ChTwoMenuSelection(ChTwoMenu());
}
else if (x == 3) {
std::cout << std::string(2, '\n');
ChThreeMenuSelection(ChThreeMenu());
}
else {
std::cout << "\nThere was an incorrect value submitted.";
std::cout << std::string(22, '\n');
MainMenuSelection(MainMenu());
}
}

Answer 1

The function MainMenuSelection( int x ) requires an int. The function call in the main function thinks it gets this by calling a function which should return an int namely int MainMenu(). But this function does not do what you should expect from a function which has been declared in this way. You should make sure that a function should ALWAYS return the value (except for a void of course).
There are static code analyzers like Cppcheck which can help you to analyse your code and find possible problems like the one you stated above.
Another tip would be to think about what happens when you execute the code. Especially when your code is still quite small you can manually go through the statements to see what path it takes, so you can find out where the program fails.