Java Reference
In-Depth Information
Display 5.4
A Static Variable
(part 2 of 2)
36
public class
StaticDemo
This is the file
StaticDemo.java
.
37
{
38
public static void
main(String[] args)
39
{
40
TurnTaker lover1 =
new
TurnTaker("Romeo", 1);
41
TurnTaker lover2 =
new
TurnTaker("Juliet", 3);
42
for
(
int
i = 1; i < 5; i++)
43
{
44
System.out.println("Turn = " + TurnTaker.getTurn());
45
if
(lover1.isMyTurn())
46
System.out.println("Love from " + lover1.getName());
47
if
(lover2.isMyTurn())
48
System.out.println("Love from " + lover2.getName());
49
}
50
}
51
}
Sample Dialogue
Turn = 1
Love from Romeo
Turn = 2
Turn = 3
Love from Juliet
Turn = 4
Another example of a static variable is given in Display 5.5. The static variable
numberOfInvocations
is used to keep track of how many invocations have been made
by all objects of the class
StaticDemo
. The program counts all invocations of the meth-
ods defined in Display 5.4, except for the method
main
.
Display 5.5
A Static Variable
(part 1 of 2)
1
public class
InvocationCounter
2{
3
private static int
numberOfInvocations = 0;
4
public void
demoMethod()
5
{
object1
and
object2
use
the same static variable
numberOfInvocations
.
6
numberOfInvocations++;
7
//In a real example, more code would go here.
8
}
