Скачать или смотреть How to Group By an Array of Objects in JavaScript

Learn how to effectively group an array of objects by a specific property in JavaScript using lodash, simplifying data management in your applications.
---
This video is based on the question https://stackoverflow.com/q/70464415/ asked by the user 'Sam Phillemon' ( https://stackoverflow.com/u/15035712/ ) and on the answer https://stackoverflow.com/a/70464638/ provided by the user 'Heartbit' ( https://stackoverflow.com/u/5405415/ ) 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 group by array of objects

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.
---
How to Group By an Array of Objects in JavaScript

When working with arrays of objects in JavaScript, a common task might involve grouping these objects based on a particular property. This is especially useful when you have related data points, and you want to club them together for easier management and analysis. In this guide, we’re going to tackle a specific example of how to achieve this using lodash, a powerful JavaScript library.

The Problem: Grouping Objects by ID

Imagine you're given an array of objects that contains employee information with duplicate id values. Here’s the structure of our sample data:

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

Your objective is to combine these entries by their id. The expected output would look something like this:

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

The Solution: Using Lodash to Group by ID

To achieve this grouping, we can utilize lodash's powerful collection manipulation capabilities. Here's a detailed breakdown of how to do it:

Step 1: Install Lodash

If you haven't installed lodash yet, you can do so using npm:

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

Step 2: Implementing the Grouping Logic

Here’s how you can use lodash to group the array of objects by the id property:

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

Explanation of the Code

_(items): We start a lodash chain on our array of objects.

groupBy('id'): This function groups the objects based on their id. The result is a new object where each key is a unique id from the original array.

map: We then map over the grouped entries to construct a new array. For each group:

label: We set the label to the id of the group.

emp: We collect all employee records into an array using _.map(), pulling out the emp data.

Result

When you run the above code, the output will be structured as intended, effectively grouping your data by id and making it easier to work with in your applications.

Conclusion

Grouping arrays of objects is a straightforward task with the right tools. Using lodash, you can efficiently manipulate and organize your data, simplifying your data structures and making them more manageable. Whether you're handling employee records, product lists, or any other dataset, the techniques discussed here can help you streamline your data operations.

Feel free to experiment with the provided code and extend it to meet your specific needs. Happy coding!