Troubleshooting my c++ programs - c++

Question

I've got these 2 programs for the current chapter in my C++ class that I cant seem to get to work and I dont understand why.
The first project requests
"Create a program that displays the appropriate shipping charge based on the zip code entered by the user. To be valid, the zip code must contain exactly five digits and the first three digits must be either “605” or “606”. The shipping charge for “605” zip codes is $25. The shipping charge for “606” zip codes is $30. Display an appropriate error message if the zip code entered is invalid. Use the sentinel value “X” to end the program."
#include <iostream>
#include <string>
using namespace std;
string zipCode = "";
string zip = "";
int main() {
cout << "ENTER AN X TO STOP ZIP CODE DATA ENTRY." << endl << endl;
cout << "Enter Zip Code: ";
getline(cin, zipCode);
while (zipCode != "x")
{
if (zipCode.length() == 5)
{
if (zipCode.find("605", 0))
{
cout << "Shipping charge is $25" << endl;
}
else if (zipCode.find("606", 0))
{
cout << "Shipping charge is $30" << endl;
}
else
cout << "Invalid Zip Code.";
}
else
{
cout << "Zip code must contain exactly 5 digits." << endl;
}
cout << "Enter Zip Code: ";
getline(cin, zipCode);
}
cout << endl << "End of Program.";
return 0;
}
I tried a similar structure for the second program and cant get it to work properly either.
Create a program that displays the color of the item whose number is entered by the user. All item numbers contain exactly seven characters. All items are available in four colors: blue, green, red, and white. The fourth character in the item number indicates the item number, as follows: a B or b indicates Blue, a G or g indicates Green, a R or r indicates Red, and a W or w indicates White. If the item number is not exactly seven characters display the appropriate error message. If the fourth character is not one of the valid color characters, display the appropriate error message. Use the sentinel value “X” to end the program.
#include <iostream>
#include <string>
using namespace std;
string itemCode = "";
int main() {
cout << "ENTER AN X TO STOP ITEM NUMBER DATA ENTRY." << endl << endl;
cout << "Enter Item Number: ";
getline(cin, itemCode);
while (itemCode != "x")
{
if (itemCode.length() == 7)
{
if (itemCode.find("B", 3) == "B")
{
cout << "Color is blue." << endl;
}
else if (itemCode.find("G", 3) == "G")
{
cout << "Color is green." << endl;
}
else if (itemCode.find("R", 3) == "R")
{
cout << "Color is Red." << endl;
}
else if (itemCode.find("W", 3) == "W")
{
cout << "Color is White." << endl;
}
else
cout << "Invalid color code found in item number.";
}
else
{
cout << "Item number must contain exactly 7 characters." << endl;
}
cout << "Enter Item Number: ";
getline(cin, itemCode);
}
cout << endl << "End of Program.";
return 0;
}

Answer 1

From glancing at your code, two obvious problems come to mind that's likely the source of your issues:
You're not checking if getline successfully grabbed the input.
Your usage of string::find's return value is wrong. You need to check for std::npos to see if there's a match or not. See here if you need more details.
For your first problem, you want something like:
while (getline(cin, zipCode) && zipCode != "x")
// ...
And removing the other getlines.
For the second, your usage should look something like:
if (zipCode.find("605", 0) != string::npos)
// ...
Your current if (zipCode.find("605", 0)) does not work because anything other than 0 or false is considered truthy. std::string::npos is typically defined as -1 which means the expression is true if the zipCode isn't found -- the opposite of your desired behavior.