OBJECT-ORIENTED THINKING - Introduction to Java Programming: Comprehensive Version - page 371

The getter methods for these data fields
are provided in the class, but omitted in the
UML diagram for brevity.

BMI

-name: String
-age: int
-weight: double
-height: double

The name of the person.
The age of the person.
The weight of the person in pounds.
The height of the person in inches.

Creates a BMI object with the specified
name, age, weight, and height.
Creates a BMI object with the specified
name, weight, height, and a default age 20.
Returns the BMI.
Returns the BMI status (e.g., normal,
overweight, etc.).

+BMI(name: String, age: int, weight:
double, height: double)
+BMI(name: String, weight: double,
height: double)
+getBMI(): double
+getStatus(): String

F IGURE 10.3

The BMI class encapsulates BMI information.

Assume that the BMI class is available. Listing 10.3 gives a test program that uses this class.

L ISTING 10.3

UseBMIClass.java
1 public class UseBMIClass {
2 public static void main(String[] args) {
3 BMI bmi1 = new BMI( "Kim Yang" , 18 , 145 , 70 );
4 System.out.println( "The BMI for " + bmi1.getName() + " is "
5 + bmi1.getBMI() + " " + bmi1.getStatus());
6
7 BMI bmi2 = new BMI( "Susan King" , 215 , 70 );
8 System.out.println( "The BMI for " + bmi2.getName() + " is "
9 + bmi2.getBMI() + " " + bmi2.getStatus());
10 }
11 }

create an object

invoke instance method

create an object

invoke instance method

The BMI for Kim Yang is 20.81 Normal
The BMI for Susan King is 30.85 Obese

Line 3 creates the object bmi1 for Kim Yang and line 7 creates the object bmi2 for Susan
King . You can use the instance methods getName() , getBMI() , and getStatus() to
return the BMI information in a BMI object.
The BMI class can be implemented as in Listing 10.4.

L ISTING 10.4

BMI.java
1 public class BMI {
2 private String name;

3 private int age;

4 private double weight; // in pounds

5 private double height; // in inches

6 public static final double KILOGRAMS_PER_POUND = 0 . 45359237 ;

7 public static final double METERS_PER_INCH = 0 . 0254 ;

8
9 public BMI(String name, int age, double weight, double height) { constructor

10 this .name = name;