added, modified, and updated

Chapter-6-Functions/Review Questions and Exercises/Programming Challenges/21.cpp

@@ -16,14 +16,13 @@
  *************************************************************/
 #include <iostream>
 #include <string>
+
 using namespace std;
 
-// Function Prototypes
-double getInfo(string, double);
+void getInfo(string, double &);
 double profit(double, double, double, double, double);
 double inputValidate(double);
-void displayCalculation(double);
-
+void displayCalculation(double, int);
 
 int main()
 {
@@ -35,98 +34,72 @@ int main()
            profit_or_loss,
            number_of_stock_sales,
            total = 0;
-
-    // Get info
-    number_of_stock_sales = getInfo("How many stock sales? ", number_of_stock_sales);
+
+    getInfo("How many stock sales? ", number_of_stock_sales);
 
     for (int i = 0; i < number_of_stock_sales; i++)
     {
         cout << "\nInfo for stock sale #" << (i + 1) << endl;
 
-        NS = getInfo("Number of shares: ", NS);
-        PP = getInfo("Purchase price per share: ", PP);
-        PC = getInfo("Purchase commission paid: ", PC);
-        SP = getInfo("Sale price per share: ", SP);
-        SC = getInfo("Sale commission paid: ", SC);
-
-        // Calculate
+        getInfo("Number of shares: ", NS);
+        getInfo("Purchase price per share: ", PP);
+        getInfo("Purchase commission paid: ", PC);
+        getInfo("Sale price per share: ", SP);
+        getInfo("Sale commission paid: ", SC);
+
         profit_or_loss = profit(NS, PP, PC, SP, SC);
-        total += profit_or_loss;
 
-        // Display
-        displayCalculation(profit_or_loss);
+        total += profit_or_loss;
 
+        displayCalculation(profit_or_loss, (i + 1));
     }
 
     cout << "\nTotal profit or loss = $"
          << total
          << endl;
-    
+
     return 0;
+} // END int main()
+
+void getInfo(string prompt, double &user_input)
+{
+    cout << prompt;
+    user_input = inputValidate(user_input);
 }
 
-/****************************************************
- * Definition for inputValidate():                  *
- * inputValidate checks user input for a double.    *
- * If a double is NOT found, a                      *
- * while loop displays an error, clears and ignores *
- * previous input, and prompts the user to try      *
- * again.                                           *
- ****************************************************/
 double inputValidate(double num1)
 {
 
-    while(!(cin >> num1))
+    while(!(cin >> num1) || num1 < 0)
     {
         cout << "Error. Number must not be "
              << " 0 or greater:";
         cin.clear();
-        cin.ignore(1234, '\n');
+        cin.ignore(numeric_limits<streamsize>::max(), '\n');
     }
 
     return num1;
 }
 
-/****************************************************
- * Definition for getInfo():                        *
- * getInfo is designed to get info from the user.   *
- * the first parameter recives an argument as a     *
- * string, which prompts the user. The second       *
- * argument receives the user input and is          *
- * validated upon receiving information.            *
- ****************************************************/
-double getInfo(string prompt, double userInput)
-{
-    cout << prompt;
-    return inputValidate(userInput);
-}
-
-/****************************************************
- * Definition for displayMenu():                    *
- * displayMenu displays a menu for user to choose   *
- * from.                                            *
- ****************************************************/
-void displayCalculation(double profit_or_loss)
-{
-    cout << "The sale of the stock resulted in "
-         << (profit_or_loss < 0 ? "LOSS." : "PROFIT.")
-         << "At $" << profit_or_loss
-         << endl;
-}
-
-/****************************************************
- * Definition for profit():                         *
- * profit calculates the profit from a sale of      *
- * stock. It accepts the number of shares (NS), the *
- * purchase price per share (PP), the purchase      *
- * commission paid (PC), the sale price per share   *
- * (SP), and the sale commission paid (SC).         *
- ****************************************************/
 double profit(double NS, 
               double PP, 
               double PC, 
               double SP, 
               double SC)
 {
+    cout << "NS = " << NS << endl; 
+    cout << "PP = " << PP << endl; 
+    cout << "PC = " << PC << endl; 
+    cout << "SP = " << SP << endl; 
+    cout << "SC = " << SC << endl;    
+
     return ((NS * SP) - SC) - ((NS * PP) + PC);
+}
+
+void displayCalculation(double profit_or_loss, int stock_number)
+{
+    cout << "The sale of stock #" << stock_number << " resulted in "
+         << (profit_or_loss < 0 ? "LOSS." : "PROFIT.")
+         << "At $" << profit_or_loss
+         << endl;
 }