Java Reference
In-Depth Information
The important difference between the
while
and
do-while
loops involves when
the controlling Boolean expression is checked. With a
while
statement, the Boolean
expression is checked
before
the loop body is executed. If the Boolean expression evaluates
to
false
, then the body is not executed at all. With a
do-while
statement, the body of
Display 3.7
Demonstration of
while
Loops and
do-while
Loops
(part 1 of 2)
1
public class
WhileDemo
2 {
3
public static void
main(String[] args)
4 {
5
int
countDown;
6 System.out.println("First while loop:");
7 countDown = 3;
8
while
(countDown > 0)
9 {
10 System.out.println("Hello");
11 countDown = countDown - 1;
12 }
13 System.out.println("Second while loop:");
14 countDown = 0;
15
while
(countDown > 0)
16 {
17 System.out.println("Hello");
18 countDown = countDown - 1;
19 }
20 System.out.println("First do-while loop:");
21 countDown = 3;
22
do
23 {
24 System.out.println("Hello");
25 countDown = countDown - 1;
26 }
while
(countDown > 0);
27 System.out.println("Second do-while loop:");
28 countDown = 0;
29
do
30 {
31 System.out.println("Hello");
32 countDown = countDown - 1;
33 }
while
(countDown > 0);
34 }
35 }
(continued)
