Скачать или смотреть How to Compare Two Set Values in the Same ArrayList in Java

Discover how to effectively compare and manipulate values in an `ArrayList` of Java objects, using a practical example with employee management.
---
This video is based on the question https://stackoverflow.com/q/69102962/ asked by the user 'Cynthia de Rooy' ( https://stackoverflow.com/u/16641923/ ) and on the answer https://stackoverflow.com/a/69165927/ provided by the user 'João Dias' ( https://stackoverflow.com/u/16572295/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: how to compare 2 set values in the same arraylist in java

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding How to Compare Two Set Values in an ArrayList in Java

When working with collections in Java, one common task is comparing values within the same ArrayList. This is especially relevant when dealing with objects that have various attributes that need to be assessed against each other. In this guide, we will tackle a specific example: comparing the planned hours and contracted hours of employee specialists stored in an ArrayList.

The Scenario

Our task involves a system that tracks Specialist employees, where each specialist has an ID, Name, contracted hours, and planned hours. The goal here is to identify which specialists have less planned hours than their contracted hours.

The Class Structure

We start with a basic structure that consists of three classes: Employee, Specialist, and Workspace. Here’s a breakdown of the essential components:

Employee Class: This serves as the parent class for our specialist.

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

Specialist Class: This class extends the Employee class and has additional functionality for managing planning and contracting of hours.

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

Workspace Class: Holds the list of specialists and oversees their combined hours.

The Main Class Implementation

In the main class, we instantiate the specialists, add them to an ArrayList, and manage their planned and contracted hours:

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

Comparing the Hours

The last part of our implementation will involve comparing the HoursPlanned to HoursWork for each specialist. We will use Java’s Stream API for this, allowing for an elegant and expressive solution.

Here’s how we can achieve this comparison:

Filter the Specialists: We will filter through the list of specialists to find those whose planned hours are less than their contracted hours.

Collect Names: After filtering, we will collect their names into a new list.

The code for comparison looks like this:

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

Conclusion

By following this approach, we have effectively compared two sets of values (planned hours vs. contracted hours) within the same ArrayList of employee specialists. This Java implementation not only demonstrates the utility of the Stream API for filtering and collecting data but also provides a practical scenario for managing employee hours efficiently.

If you’ve enjoyed this breakdown, feel free to explore more about Java collections and their many powerful features!