Classes and Objects: Adding Letter Counts

[yitriana]

Homework Statement

Create a class that adds counts of letters or two Strings, and create an object which represents sum of the counts.

Homework Equations

n/a

The Attempt at a Solution

i am confused about how to construct objects in a class itself, and not in client code.
as in this site,

http://math.hws.edu/javanotes/c5/s2.html

adding the roll produced by dice is done by client, but not by the class.

further, if objects are instances of the class, then the client must call the class and add whatever it returns or whatever from the methods.

but how can a class do this?

i am instructed to "Constructs and returns a new LetterInventory object that represents the sum of this letter inventory and the other given LetterInventory. The counts for each letter should be added together. The two LetterInventory objects being added together (this and other) should not be changed by this method"

 

[Valkarie]

so how can an object be created inside the class? any help will be much appreciated. public class LetterInventory { private int[] counts; private String alphabet; private int size; public LetterInventory(String data) { alphabet = "abcdefghijklmnopqrstuvwxyz"; counts = new int[alphabet.length()]; size = 0; data = data.toLowerCase(); for (int i=0; i<data.length(); i++) { int index = alphabet.indexOf(data.charAt(i)); if (index != -1) { counts[index]++; size++; } } } public LetterInventory add(LetterInventory other) { // constructs and returns a new LetterInventory object that represents the sum of this letter inventory and the other given LetterInventory. // The counts for each letter should be added together. The two LetterInventory objects being added together (this and other) should not be changed by this method }}

 

[Mene]

In order to construct objects in a class, you can create a constructor method within the class. This method will be responsible for creating new instances of the class and initializing their properties. In this case, the constructor method would take in two String parameters, representing the two strings whose letter counts will be added together.

As for the class itself, it can have methods that perform the actual addition of the letter counts. For example, you could have a method called "addLetterCounts" which takes in two LetterInventory objects as parameters and returns a new LetterInventory object representing the sum of the two. This method would use the properties and methods of the LetterInventory class to add the letter counts together.

In terms of the client code, it would call the constructor method to create the LetterInventory objects and then call the "addLetterCounts" method to add their letter counts together. The client code would then have access to the new LetterInventory object representing the sum of the counts.

It's important to remember that the class itself is not responsible for calling its own methods or creating its own objects. This is the job of the client code. The class simply provides the structure and functionality for creating and manipulating objects of that type.