INTRODUCTION TO OBJECTS AND INPUT/OUTPUT - Java Programming: From Problem Analysis to Program Design - page 160

PROGRAMMING EXAMPLE: Student Grade
Write a program that reads a student's first and last names followed by five test scores.
The program should output the student's first name, last name, the five test scores,
and the average test score. Output the average test score with two decimal places.
The data to be read is stored in a file named test.txt ; the output should be stored
in a file named testavg.out .

Input: A file containing the student's first name, last name, and the five test scores

Output: The student's first name, last name, five test scores, and the average of the five
test scores, saved to a file

To find the average of the five test scores, you add the test scores and divide the sum
by 5. The input data is in the following form: the student's first name, followed by
the last name, followed by the five test scores. Therefore, we read the student's first
name, followed by the last name, followed by the five test scores. This problem
analysis translates into the following algorithm:

PROBLEM
ANALYSIS
AND
ALGORITHM
DESIGN

1. Get the student's first name, last name, and the five test scores.
2. Output the student's first name, last name, and the five test scores.
3. Calculate the average.
4. Output the average.
You output the average test score in the fixed-decimal format with two decimal places.

VARIABLES The program needs to read a student's first name, last name, and five test scores.
Therefore, you need two variables to store the student's first name and last name, and
five variables to store the five test scores. To find the average, you must add the five
test scores and then divide the sum by 5 . Thus, you also need a variable to store the
average test score. Furthermore, because the input data is in a file and the output is to
be stored in a file, you must declare and initialize the appropriate variables. The
program needs at least the following variables:

double test1, test2, test3, test4, test5; //variables to store
//five test scores

double average; //variable to store average test score

String firstName; //variable to store the first name

String lastName; //variable to store the last name

Scanner inFile = new Scanner( new FileReader("test.txt"));

PrintWriter outFile = new PrintWriter("testavg.out");