Java Reference
In-Depth Information
To calculate the value of this expression, the computer divides the weight by the
square of the height and then multiplies the result of that operation by the literal
value
703
. The result is stored in the variable
bmi
. So, after the computer has exe-
cuted the third assignment statement, the memory looks like this:
height 70.0
weight 195.0
bmi 27.976530612244897
The last two lines of the program report the BMI result using
println
statements:
System.out.println("Current BMI:");
System.out.println(bmi);
Notice that we can include a variable in a
println
statement the same way that
we include literal values and other expressions to be printed.
As its name implies, a variable can take on different values at different times. For
example, consider the following variation of the BMI program, which computes a new
BMI assuming the person lost 15 pounds (going from 195 pounds to 180 pounds).
1
public class
BMICalculator2 {
2
public static void
main(String[] args) {
3 // declare variables
4
double
height;
5
double
weight;
6
double
bmi;
7
8 // compute BMI
9 height = 70;
10 weight = 195;
11 bmi = weight / (height * height) * 703;
12
13 // print results
14 System.out.println("Previous BMI:");
15 System.out.println(bmi);
16
17 // recompute BMI
18 weight = 180;
19 bmi = weight / (height * height) * 703;
20
21 // report new results
22 System.out.println("Current BMI:");
23 System.out.println(bmi);
24 }
25 }
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