c++ While loops prints the couts twice - c++

Question

In my code, the while loop prints the cout twice when it should print it once, as well as the function's couts. I don't understand why it's doing this - it is supposed to display
What would you like to do?
Deposit
Withdraw
Cancel
But, it displays that twice.
while (yesNo == 'Y') {
cout << "What would you like to do?"
<< endl
<< endl;
menu();
getline(cin, bankChoice);
if (bankChoice == "Withdraw")
{
withdrawTotal = withdraw(bankAmount);
bankAmount = withdrawTotal;
cout << "You now have $"
<< bankAmount
<< " in your account."
<< endl;
cout << "Would you like to do anything else?"
<< endl
<< "Y/N: ";
cin >> yesNo;
}
if (bankChoice == "Deposit")
{
depositTotal = deposit(bankAmount);
bankAmount = depositTotal;
cout << "You now have $"
<< bankAmount
<< " in your account."
<< endl;
cout << "Would you like to do anything else?"
<< endl
<< "Y/N: ";
cin >> yesNo;
}
if (bankChoice == "Cancel") {
return 0;
}
}
That is the loop I am using. If additional code is needed I can post it as well, but this is the part that is causing the issue. I've tried the code without it and it works fine, but I'd like to get the code to loop until the user enters 'N'.

Answer 1

You are using both std::getline and operator>> to read from std::cin. operator>> does not consume the trailing newline, so the next call to std::getline() will immediately read the following newline and interpret it as an empty line of text that was entered. This will run through the loop, and go back up to the top, for the second prompt.
Never use operator>> with std::cin when you intend to read a single line of text.
The following short example demonstrates this point:
#include <iostream>
#include <string>
int main()
{
char c;
std::string l;
std::cin >> c;
std::cout << "A line of text please: ";
std::getline(std::cin, l);
}
Run it, enter "Y", and try to figure it out, yourself, why the program terminates immediately.
Once again: don't use operator>> to read lines of text from std::cin. It is a recipe for grief, and bugs.

Answer 2

In addition to Sam's answer, I'd like to recommend that you extract common functionality outside your two if statements:
std::string yesNo;
while (yesNo.compare("Y") == 0) {
cout << "What would you like to do?"
<< endl
<< endl;
menu();
getline(cin, bankChoice);
if (bankChoice == "Cancel")
return 0;
if (bankChoice == "Withdraw") {
withdrawTotal = withdraw(bankAmount);
bankAmount = withdrawTotal;
}
if (bankChoice == "Deposit") {
depositTotal = deposit(bankAmount);
bankAmount = depositTotal;
}
cout << "You now have $"
<< bankAmount
<< " in your account."
<< endl;
cout << "Would you like to do anything else?"
<< endl
<< "Y/N: ";
std::getline(std::cin, yesNo);
}