Description: Unit 9 – Java Arrays and Data Files

 

Description: Unit 9 – Java Arrays and Data Files

This unit is really about three different topics that are related to one another – arrays in Java, simple text files in Java, and modular programing in java (Java methods).

The unit has a programming project spread over three related programming assignments, each worth 10 points.  

In the first assignment, you will create a Java program that works with a small array of data containing five test scores.   It will get data from user input do some calculations, and then print the results. 

In the second assignment, you will modify a copy of the first assignment to load the data from a data file into an array, and then output the results to a data file.  

In the third assignment, you will decompose a copy of the second assignment into separate methods in Java.

Our goal is to have a good modular program that loads stored data from a fie into an array, works with the data, then sends results to another data file.  Doing this in three parts will allow you to focus on one aspect of the problem at a time. 

There are reading assignments in Zybooks, but the two chapters from the Java Learning Kit – Chapter 5 – and Chapter 6 are your best source for learning this material.  They cover the things you need to learn to complete this project and have good sample programs.

Your tasks are to:

  1. Read Zybooks Assginment 11 – Arrays in Java.
  2. Read the material in JLK Chapter 6 about arrays in Java.
  3. Complete the Java Arrays Programming assignment.
  4. Read the material in Chapter 6 about text files in Java.
    There is no corresponding Zybooks assignment.
  5. Complete the Java Text Files Programming assignment.
  6. Read the Zybooks Assignment 12 – Methods in Java
  7. Read the material in JLK Chapter 5 about methods in Java.
  8. Complete the Java Methods programming assignment.

It may seem like their is a lot to do here but the assignments are each simple and build on one another.

assignments:

 #1

You should complete Zybooks Assignment 11 – Arrays in Java and read lessons 6.1, 6.2, and 6.3 in JLK Chapter 6 about arrays in Java before starting this assignment.

Your task is to create a Java I-P-O program that works with a small array of data containing five test scores.

Your program should:

  1. contain a for loop to read five test score into an array from the user. The array should be a floating point array with five elements.
  2. Using second for loop, calculate the average score, highest score, and lowest score in the array. JLK lesson 6.3 is a good guide for doing this.
  3. print the results.

You should submit a zipped copy of your IntelliJ project folder.

#2

You should read lesson 6.5  Text File Input and Output in Java before starting this assignment. Reading Lab 6.6 will also be helpful. There is no corresponding Zybooks assignment.

Your task is to modify the program from the Java Arrays programming assignment  to use text files for input and output. I suggest you save acopy of the original before modifying the software.

Your modified program should:

  1. contain a for loop to read the five test score into the array from a text data file. 

    You will need to create and save a data file for the program to use. It should have one test score on each line of the file.  You can type and save the text file with any text editor, such as Notepad or Notepad++.  NotePad++ is a good program to have on your computer, It can be downloaded freely from: https://notepad-plus-plus.org  (Links to an external site.)
    It should be saved or copied to the same folder as your Java source code file within you Intellij project.

  2. Contain a second for loop, calculate the average score, highest score, and lowest score in the array. This part  of your program does not need to change from the previous assignment.
  3. output the results to a new text file. You can decide the name of the file. You should only use a local file name and the file will then be created in your IntelliJ project folder.

You should submit a zipped copy of your IntelliJ project folder, which should contain the two data files within the project..

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#3

You should complete Zybooks Assignment 12 – Methods in Java and read lessons JLK Chapter 5 – Methods and Modularity in Java before starting this assignment.

Your task is to modify the program from the Java Text files programming assignment  to contain several methods for different parts of the program.I suggest you save a copy of the original before modifying the software.

Your modified program should have the following six methods:

  • a method with a for loop to read the five test score into the array from a text data file.  The array should be declared in the main method and passed as a parameter to this method.
  • three separate methods to each calculate and return one of the following: the average score, highest score, and lowest score . Each method should contain a for loop to calculate and return one of the values to the main method. You can copy and edit he existing loop form the previous program for each of these methods.
  • a method to output the results to a new text file, as the main method did in the previous program. You basically need to move the code to do this into a new method.
  • the main method, which has the necessary variables and which calls the other methods as needed, passing values to those methods and receiving returned value from the methods as needed. 

Unlike Python functions, methods do not need to appear before they are called in a program file. In fact, it is common practice in Java to put the main() method as the first method in Java program, similar to what is done in the payMethods sample program in the chapter.

You should submit a zipped copy of your IntelliJ project folder, which should contain will contain the two data files within the project..

You should submit a zipped copy of your IntelliJ project folder.

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