In this lesson, you learned about the fundamental data variables found in most C++ programs. You learned the following:
Project 3 Listing. Introduction to data and I/O.
1: // Filename: PROJECT3.CPP
2: // This program defines different kinds of variables and
3: // lets the user's keyboard input fill the variables with
4: // values. Subsequent couts print the data in the variables.
5: #include <iostream.h>
6:
7:
8: void main()
9: {
10: char prodName[12];
11: int count;
12: float price;
13: float totalInv;
14: cout << "Inventory Calculation" << endl;
15: cout << "---------------------" << endl << endl;
16:
17: cout << "This program calculates an inventory's cost."
18: << endl << endl;
19: cout << "What is the product name? ";
20: cin >> prodName;
21: cout << "How many " << prodName << "s are there? ";
22: cin >> count;
23: cout << "How much does each " << prodName << " cost? ";
24: cin >> price;
25: // Ready to extend the inventory cost
26: totalInv = count * price;
27: cout.precision(2);
28: cout.setf(ios::showpoint);
29: cout.setf(ios::fixed);
30: cout << endl << "The total valuation for " << prodName
31: << " is $" << totalInv << endl;
32: return;
33: }
Output
Inventory Calculation --------------------- This program calculates an inventory's cost. What is the product name? Widget How many Widgets are there? 3 How much does each Widget cost? 3.30 The total valuation for Widget is $9.90
Description
1: A Visual C++ comment that includes the program's filename.
2: A C++ comment that begins the program's description.
3: The program's description continues.
4: The program's description continues.
5: cout needs information in the IOSTREAM.H header file.
6: Extra blank lines make your program more readable.
7: Extra blank lines make your program more readable.
8: All functions have names, and the first function in all C++ programs is main().
9: All functions begin with a left brace.
10: Defines a character array that can hold a string as long as 11 characters plus a terminator.
11: Defines an integer variable that will hold an inventory count.
12: Defines a floating-point variable that will hold a floating-point price per inventory item.
13: Defines a floating-point variable that will hold a floating-point total price of all the items.
14: The first line of a title is printed.
15: The title appears underlined on the screen due to the well-placed hyphens.
16: Extra blank lines make your program more readable.
17: A printed message to describe the program's goal.
18: Two newlines that are a continuation of the previous line.
19: A prompt for the item name.
20: Takes the user's input and stores the item name in a character array.
21: A prompt for the item's inventory count.
22: The item's count is entered.
23: The cost of each item is requested.
24: The user enters the floating-point price per item.
25: A comment describing the upcoming program section.
26: The total inventory price for the item is calculated and stored in totalInv.
27: The dollar values require two decimal places to be printed.
28: An I/O manipulator that ensures a decimal point.
29: An I/O manipulator that ensures fixed point (as opposed to scientific notation) displays.
30: You can continue couts on more than one line, as done here, as long as you break the line at a <<.
31: The cout continues.
32: The program returns to QuickWin.
33: All program functions (main() here) end with a closing brace.
5: Add ample comments at the top of your programs that give a brief description of the code.
22: Notice how the item name, obtained in line 20, is embedded in the prompt.
