C++ Primer Plus

Programming Exercises

1. Write a C++ program that displays your name and address (or if you value your privacy, a fictitious name and address).

2. Write a C++ program that asks for a distance in furlongs and converts it to yards. (One furlong is 220 yards.)

3. Write a C++ program that uses three user-defined functions (counting main() as one) and produces the following output:

Three blind mice

Three blind mice

See how they run

See how they run

One function, called two times, should produce the first two lines, and the remaining function, also called twice, should produce the remaining output.

4. Write a program that asks the user to enter his or her age. The program then should display the age in months:

Enter your age: 29

Your age in months is 384.

5. Write a program that has main() call a user-defined function that takes a Celsius temperature value as an argument and then returns the equivalent Fahrenheit value. The program should request the Celsius value as input from the user and display the result, as shown in the following code:

Please enter a Celsius value: 20

20 degrees Celsius is 68 degrees Fahrenheit.

For reference, here is the formula for making the conversion:

Fahrenheit = 1.8 × degrees Celsius + 32.0

6. Write a program that has main() call a user-defined function that takes a distance in light years as an argument and then returns the distance in astronomical units. The program should request the light year value as input from the user and display the result, as shown in the following code:

Enter the number of light years: 4.2

4.2 light years = 265608 astronomical units.

An astronomical unit is the average distance from the earth to the sun (about 150,000,000 km or 93,000,000 miles), and a light year is the distance light travels in a year (about 10 trillion kilometers or 6 trillion miles). (The nearest star after the sun is about 4.2 light years away.) Use type double (as in Listing 2.4) and this conversion factor:

1 light year = 63,240 astronomical units

7. Write a program that asks the user to enter an hour value and a minute value. The main() function should then pass these two values to a type void function that displays the two values in the format shown in the following sample run:

Enter the number of hours: 9

Enter the number of minutes: 28

Time: 9:28

3. Dealing with Data

In this chapter you’ll learn about the following:

• Rules for naming C++ variables

• C++’s built-in integer types: unsigned long, long, unsigned int, int, unsigned short, short, char, unsigned char, signed char, bool

• C++11’s additions: unsigned long long and long long

• The climits file, which represents system limits for various integer types

• Numeric literals (constants) of various integer types

• Using the const qualifier to create symbolic constants

• C++’s built-in floating-point types: float, double, and long double

• The cfloat file, which represents system limits for various floating-point types

• Numeric literals of various floating-point types

• C++’s arithmetic operators

• Automatic type conversions

• Forced type conversions (type casts)

The essence of object-oriented programming (OOP) is designing and extending your own data types. Designing your own data types represents an effort to make a type match the data. If you do this properly, you’ll find it much simpler to work with the data later. But before you can create your own types, you must know and understand the types that are built in to C++ because those types will be your building blocks.

The built-in C++ types come in two groups: fundamental types and compound types. In this chapter you’ll meet the fundamental types, which represent integers and floating-point numbers. That might sound like just two types; however, C++ recognizes that no one integer type and no one floating-point type match all programming requirements, so it offers several variants on these two data themes. Chapter 4, “Compound Types,” follows up by covering several types that are built on the basic types; these additional compound types include arrays, strings, pointers, and structures.

Of course, a program also needs a means to identify stored data. In this chapter you’ll examine one method for doing so—using variables. Then you’ll look at how to do arithmetic in C++. Finally, you’ll see how C++ converts values from one type to another.

Simple Variables

Programs typically need to store information—perhaps the current price of Google stock, the average humidity in New York City in August, the most common letter in the U.S. Constitution and its relative frequency, or the number of available Elvis impersonators. To store an item of information in a computer, the program must keep track of three fundamental properties:

• Where the information is stored

• What value is kept there

• What kind of information is stored