Question

CS

Assignment 2.1
Class to Manage an Array of Integers
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For this assignment, you will write a class called SumArrayClass that manages an array of integers. You will also write a test program called SumArrayClassTest that demonstrates that your class works as designed.
Before writing any code:
Create a new project SumArray
Add one source file. Replace the shell code with the entire contents of SumArray.java. NOTE: It is a file with a main() method.
Run SumArray. Its operation and output will be similar to SumArrayClassTest
NOTE: Remember to add your name and date as comments at the beginning of all source files; e.g.
// John Doe 8/20/21
You will write a SumArrayClass class that has the following features:
Contains a private instance variable that is the reference to an integer array
A constructor that
Has one integer parameter which is the size of the integer array
Instantiates an integer array of the specified size using the new operator. The value is assigned to the private instance variable defined in Step 1

A method called fillArray to ask the user to fill the array with integers.
A method called printArray that prints out the values stored in the array.
A method called sumArray that return the sum of the integers in the array
NOTE: None of the methods will have any parameters
Your test program SumArrayClassTest will perform the following tasks:
Ask the user for the number of integers to store
Instantiate an object of your "manager" class SumArrayClass
Allow the user to fill the array with their integer values.
Print out the values currently stored in the array.
Print out the sum of the values currently stored in the array.
A run of the program will look the same as that for SumArray; to the user of the test program, it will not be obvious that the "work" is being done using a manager class.

An important concept with this type of "manager" class is that the test program (or any program using an object of this class) cannot directly access the array in the object. In fact, the user would not even know (perhaps) that an array was being used; the designer of the manager class could use some other type of data structure. All interaction between the test program and the object’s array will be via the class methods.

Answer 1

The CSAssignment 2.1 involves creating a SumArrayClass to manage an integer array and a SumArrayClassTest to demonstrate its functionality. The SumArrayClass encapsulates the array and provides methods for input, output, and sum calculation without exposing the array to the test program directly.

Step-by-step explanation:

Creating the SumArrayClass

For the CSAssignment 2.1, the task involves writing a SumArrayClass to manage an array of integers and a test program named SumArrayClassTest. The SumArrayClass will use a private integer array, a constructor to initialize the array size, and several methods. The fillArray method will allow user input to populate the array, the printArray method will display the array contents, and the sumArray method will calculate the sum of the array elements. The SumArrayClassTest will then use these methods to demonstrate that the SumArrayClass is functioning correctly, without giving the test program direct access to the array, encapsulating the array management within the SumArrayClass.

Steps to Implement SumArrayClass

1. Create a project named SumArray.
2. Add a source file with main() method from the SumArray.java content.
3. Write the SumArrayClass with a private integer array.
4. Implement a constructor for array initialization.
5. Create the fillArray, printArray, and sumArray methods.

Steps for the Test Program SumArrayClassTest

1. Ask the user to specify the array size.
2. Create an instance of the SumArrayClass.
3. Invoke fillArray to collect user-input integers.
4. Use printArray to show the array contents.
5. Display the sum of the array elements with sumArray.