How to Keep a Running Average of Values in Java

Learn how to maintain a running average of values in Java using basic methods like get/set and ArrayLists, perfect for your school assignments.
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How to Keep a Running Average of Values in Java: A Simple Guide

In Java programming, especially for beginners, you may find yourself needing to maintain a running average of values. This is a common task in various applications, including averages for ratings, scores, or any other metrics that are provided over time. If you're facing challenges with this in your Java assignment, worry not! In this guide, we will simplify the process of keeping a running average, step by step.

The Problem

You've been tasked with creating a program that accumulates ratings through repeated function calls. However, every time you input a new rating using the setRate method, it replaces the previous one instead of storing it for an average calculation. You've realized that you need a way to retain all the rates inputted over time and compute the average from these.

The Solution

To effectively maintain a running average, we will follow a straightforward approach by keeping track of two main components:

The sum of all inputs received so far.

The number of inputs that have been received.

Step-by-Step Implementation

Let’s break down the implementation. Below is the code template we will enhance to achieve our goal:

[[See Video to Reveal this Text or Code Snippet]]

Code Breakdown

Variables Initialization:

ratesSum: This variable will store the cumulative sum of all rates inputted.

rateCount: This variable will keep track of how many rates have been entered.

Get Rate Method (getRate):

Simply returns the current rate that you have set.

Set Rate Method (setRate):

This method not only sets the current rate but also updates both ratesSum and rateCount.

Whenever you call this method, it adds the new rate to the total sum (ratesSum) and increases the count.

Get Average Rate Method (getAverageRate):

This method calculates the average by dividing ratesSum by rateCount.

A crucial check is included to avoid division by zero, which would occur if no rates have been added yet.

Conclusion

By following the above steps and understanding the code provided, you can easily create a running average of values in Java. This approach is not just effective but also simple enough for school assignments, especially when you're encouraged to use basic commands like get/set and ArrayLists.

So, whenever you're tasked with averaging inputs, remember to track both the sum of the inputs and the count of how many inputs you've received. Happy coding!