- 4.1 Introduction
- 4.2 Classes, Objects, Methods, Properties and Instance Variables
- 4.3 Declaring a Class with a Method and Instantiating an Object of a Class
- 4.4 Declaring a Method with a Parameter
- 4.5 Instance Variables and Properties
- 4.6 UML Class Diagram with a Property
- 4.7 Software Engineering with Properties and set and get Accessors
- 4.8 Auto-Implemented Properties
- 4.9 Value Types vs. Reference Types
- 4.10 Initializing Objects with Constructors
- 4.11 Floating-Point Numbers and Type decimal
- 4.12 Wrap-Up
- Summary
- Terminology
- Self-Review Exercises
- Answers to Self-Review Exercises
- Exercises
- Making a Difference Exercises
This chapter is from the book
This chapter is from the book
This chapter is from the book
Making a Difference Exercises
4.15 |
(Target-Heart-Rate Calculator) While exercising, you can use a heart-rate monitor to see that your heart rate stays within a safe range suggested by your trainers and doctors. According to the American Heart Association (AHA) (www.americanheart.org/presenter.jhtml?identifier=4736), the formula for calculating your maximum heart rate in beats per minute is 220 minus your age in years. Your target heart rate is a range that is 50–85% of your maximum heart rate. [Note: These formulas are estimates provided by the AHA. Maximum and target heart rates may vary based on the health, fitness and gender of the individual. Always consult a physician or qualified health care professional before beginning or modifying an exercise program.] Create a class called HeartRates. The class attributes should include the person's first name, last name, year of birth and the current year. Your class should have a constructor that receives this data as parameters. For each attribute provide a property with set and get accessors. The class also should include a property that calculates and returns the person's age (in years), a property that calculates and returns the person's maximum heart rate and properties that calculate and return the person's minimum and maximim target heart rates. Write an application that prompts for the person's information, instantiates an object of class Heart-Rates and prints the information from that object—including the person's first name, last name and year of birth—then calculates and prints the person's age in (years), maximum heart rate and targetheart-rate range. |
4.16 |
(Computerization of Health Records) A health care issue that has been in the news lately is the computerization of health records. This possibility is being approached cautiously because of sensitive privacy and security concerns, among others. [We address such concerns in later exercises.] Computerizing health records could make it easier for patients to share their health profiles and histories among their various health care professionals. This could improve the quality of health care, help avoid drug conflicts and erroneous drug prescriptions, reduce costs and, in emergencies, could save lives. In this exercise, you'll design a "starter" HealthProfile class for a person. The class attributes should include the person's first name, last name, gender, date of birth (consisting of separate attributes for the month, day and year of birth), height (in and weight (in pounds). Your class should have a constructor that receives this data. For each attribute provide a property with set and get accessors. The class also should include methods that calculate and return the user's age in years, maximum heart rate and target-heart-rate range (see Exercise 4.15), and body mass index (BMI; see Exercise 3.31). Write an application that prompts for the person's information, instantiates an object of class HealthProfile for that person and prints the information from that object—including the person's first name, last name, gender, date of birth, height and weight—then calculates and prints the person's age in years, BMI, maximum heart rate and target-heart-rate range. It should also display the "BMI values" chart from Exercise 3.31. |