John A.

Implement two classes and use an array of objects to count the number of times each letter occurs in a text file.

Counter - each counter should maintain a single count (don't allocate an array here)

Counter() - constructor that initializes the count to 0

void incrementCount() - increases the count by 1

void resetCount() - sets the count to 0

String toString() - returns a String representation of the count (e.g., "13")

boolean equals(Counter c) - returns true if both Counters store the same count

You will use the Counter class in a separate class called LetterInventory, which has the following methods:

LetterInventory - stores the count for all 26 letters

LetterInventory() - constructs the inventory (an array of 26 Counter objects)

void countOccurrences(Scanner file) - counts the frequency of each letter in a file

void displayTable() - displays the frequencies of each letter in the inventory

void resetInventory() - resets all of the counts to 0

Your LetterInventory class must use an array of Counter objects. Note that there is no nextChar method in the Scanner class. You must use the next() method and then use a loop through the characters of the token that is returned. Ignore any character that is not a letter. You should also treat 'a' and 'A' as the same letter.

To convert a letter into an integer index, subtract 'a' or 'A' from it. The expression (letter - 'a') will yield an integer between 0 and 25 for any lowercase letter. Should output:

a: xx

b: xx

c: xx

d: xx

ect..

Drive Code:

import java.util.Scanner;
import java.io.File;

public class LetterCounter {
public final static String filename = "testFile.txt";

// Driver to test LetterInventory class
public static void main(String[] args) {
Scanner inputFile = null;
try {
inputFile = new Scanner(new File(filename));
} catch (Exception e) {
System.out.println("File could not be opened: " + filename);
System.exit(0);
}

LetterInventory inventory = new LetterInventory();
inventory.countOccurrences(inputFile);
inventory.displayTable();
inventory.resetInventory();
}
}