BookRatingWithFileIO Program
Description
An external data file BookRating_Data.txt contains the book rating information for a number of books.This is program is similar to the previous program, but the book's information is stored in the data file and the number of books is unknown.
The program uses two arrays to store title and rating for a number of books, and uses several methods to do the following:
Determine the number books in the data file
Fill in the arrays with the data in the date file
Calculate the average rating
Find the the book with the highest rating (assume there is no tie)
Print books title and rating
Fill in the arrays with the data in the date file
Calculate the average rating
Find the the book with the highest rating (assume there is no tie)
Print books title and rating
Associated Concepts:
Array
File Input / Output
File Input / Output
Algorithm:
main method:
countBooks method definition:
populateArray method definition:
printArray method definition:
sumArray method definition:
indexOfHighestRating method definition:
Call method to determine the number of books in the data file
Based on the number of books, create two arrays to store books information
Call methods to:
Based on the number of books, create two arrays to store books information
Array of String to store titles
Array of double to store ratings
Array of double to store ratings
Call methods to:
Read data in the data file to populate the arrays
Print the array elements
Calculate the total rating
Find the index of the book with the highest rating (assume there is no tie) and print the result
Print the average rating
Print the array elements
Calculate the total rating
Find the index of the book with the highest rating (assume there is no tie) and print the result
Print the average rating
countBooks method definition:
Declare variable count and initialize it to 0
Read the top line of data without storing it
while loop: as long as the data file has data item
Read the top line of data without storing it
while loop: as long as the data file has data item
Read the entire line of data without storing it
Increment count
Increment count
populateArray method definition:
Read the top line of data without storing it
Declare variable i and initialize it to 0
while loop: as long as the data file has data item
Declare variable i and initialize it to 0
while loop: as long as the data file has data item
Read title and rating from the data file
Assign them to the array cell i
Increment i
Assign them to the array cell i
Increment i
printArray method definition:
For i = 0 to last index of array cell
Print the array elements at i
sumArray method definition:
Declare variable sum and initialize it to 0
For i = 0 to last index of array cell
return sum
For i = 0 to last index of array cell
Add the current rating at i to sum
return sum
indexOfHighestRating method definition:
Declare variable maxIndex and assign it to 0
(Assume the first element is the highest)
For i = 1 to last index of array cell
return maxIndex
For i = 1 to last index of array cell
If the current element at i is greater than
the current highest element
Update maxIndex to the current index i
Update maxIndex to the current index i
return maxIndex
Source Code
Input File BookRating_Data.txt:
Sample Run
