Java Reference
In-Depth Information
4
5
public
class
ClassAverage
6
{
7
public static void
main(String[] args)
8
{
9
// create Scanner to obtain input from command window
10
Scanner input =
new
Scanner(System.in);
11
12
// initialization phase
13
int
total =
0
;
// initialize sum of grades
14
int
gradeCounter =
0
;
// initialize # of grades entered so far
15
16
// processing phase
17
// prompt for input and read grade from user
System.out.print(
"Enter grade or -1 to quit: "
);
int
grade = input.nextInt();
18
19
20
21
// loop until sentinel value read from user
22
while
(grade !=
-1
)
23
{
24
total = total + grade;
// add grade to total
25
gradeCounter = gradeCounter +
1
;
// increment counter
26
27
// prompt for input and read next grade from user
System.out.print(
"Enter grade or -1 to quit: "
);
grade = input.nextInt();
28
29
30
}
31
32
// termination phase
33
// if user entered at least one grade...
34
if
(
gradeCounter !=
0
)
35
{
36
// use number with decimal point to calculate average of grades
double
average = (
double
) total / gradeCounter;
37
38
39
// display total and average (with two digits of precision)
40
System.out.printf(
"%nTotal of the %d grades entered is %d%n"
,
41
gradeCounter, total);
42
System.out.printf(
"Class average is %.2f%n"
, average);
43
}
44
else
// no grades were entered, so output appropriate message
45
System.out.println(
"No grades were entered"
);
46
}
47
}
// end class ClassAverage
Enter grade or -1 to quit:
97
Enter grade or -1 to quit:
88
Enter grade or -1 to quit:
72
Enter grade or -1 to quit:
-1
Total of the 3 grades entered is 257
Class average is 85.67
Fig. 4.10
|
Solving the class-average problem using sentinel-controlled repetition. (Part 2 of 2.)
