function for validation input c++ simple [closed] - c++

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to some this might seem simple, but to me I can't really seem to figure out why this isn't working. I know I could just copy and paste every time inside the while loop to get the result I want, but I've been told that if you have to repeat something more than one time to write a function! My code will double print the number and even though someone would type 8 it will still go into the while loop. Hoping someone can explain why this is happening to me.
int main()
{
int option = selectionHelper();
cout << selectionHelper() << endl;
cout << endl;
if(option == 8)
{
cout << "Exiting program..." << endl;
cout << endl;
cin >> option;
}
while (option != 8)
{
if (option == 1){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else if(option == 2){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else if(option == 3){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else if(option == 4){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else if(option == 5){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else if(option == 6){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else if(option == 7){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else{
cout << "Invalid input... Please try again..." << endl;
cout << endl;
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}//end else if statement
}//end while loop
}//end function main
and now for my function:
int selectionHelper()
{
int option;
cout << "1. Initialize seating for new performance." << endl;
cout << "2. View seating chart." << endl;
cout << "3. Reserve seats." << endl;
cout << "4. Calculate tickets remaining in row." << endl;
cout << "5. Calculate tickets remaining in theater." << endl;
cout << "6. Calculate total tickets sold." << endl;
cout << "7. Calculate ticket sales." << endl;
cout << "8. Exit program." << endl;
cout << "Option: " << endl;
cin >> option;
return option;
}//end selectionHelper
Thank you for looking at my post!

Answer 1

This answer and others will tell you what code to write to fix your problem. If you should encounter similar problems in the future, try walking through your code with a debugger. (Experience helps too.) Regarding code redundancy: first, it's good that you used the selectionHelper() method. That shows you have good instincts. Here's what you can do further:
Look for lines of code that are the same or differ only by a variable.
Consider condensing them in the following ways:
Can you use a for-loop?
Can you put the code in a method (possibly abstracting out a variable?)
Can you use a broader conditional statement? (That's what you have going on here: if a number is 1, 2, 3, 4, 5, 6, or 7, it's also >0 and <7. That's why we have ranges.)
The program keeps going when they enter 8 because you ask them to input a number after they input 8! So your first chunk of code can be simpler:
int option = selectionHelper();
cout << option << endl <<endl; // <-- output option, don't call selectionHelper() here again, that's why you get double printing
if(option == 8)
{
cout << "Exiting program..." << endl;
cout << endl;
//cin >> option; // <-- don't input here again!
}
The key here to simplifying your code is to recognize that you only write different code in a few cases. So, here's your while loop:
while (option != 8)
{
if (option > 0 && option < 8){
cout << selectionHelper() << endl;
cout << endl;
cin >> option;
}else{
cout << "Invalid input... Please try again..." << ends << endl;
cout << selectionHelper() << endl << endl;
cin >> option;
}//end else if statement
}

Answer 2

You must modify your code in the following ways:
int option = selectionHelper();
cout << option << endl;
And also:
if(option == 8)
{
cout << "Exiting program..." << endl;
}
You can simplify your code down to (using partly the simplification made by cuniculus but also fixing the mistake in your own code of wrong using option):
#include <iostream>
using namespace std;
int selectionHelper()
{
int option;
cout << "1. Initialize seating for new performance." << endl;
cout << "2. View seating chart." << endl;
cout << "3. Reserve seats." << endl;
cout << "4. Calculate tickets remaining in row." << endl;
cout << "5. Calculate tickets remaining in theater." << endl;
cout << "6. Calculate total tickets sold." << endl;
cout << "7. Calculate ticket sales." << endl;
cout << "8. Exit program." << endl;
cout << "Option: " << endl;
cin >> option;
return option;
}//end selectionHelper
int main()
{
int option = selectionHelper();
while (option != 8)
{
if (option > 0 && option < 8){
option = selectionHelper();
}else{
cout << "Invalid input... Please try again..." << ends << endl;
option = selectionHelper();
}//end else if statement
}
cout << "Exiting program..." << endl;
return 0;
}//end function main
Your mistake was basically in calling selectionHelper too many times, when only once is needed to set the option variable. You have a similar thing going on in your whole if-else structure - but I'll leave it up to you to fix that if needed, the solution is the same.