Скачать или смотреть How to Get a Unique Array from a Nested Object in JavaScript with Lodash

Learn how to extract unique operation names and labels from a nested object array in JavaScript using lodash or vanilla JavaScript methods.
---
This video is based on the question https://stackoverflow.com/q/62279396/ asked by the user 'Skoby' ( https://stackoverflow.com/u/10305140/ ) and on the answer https://stackoverflow.com/a/62279485/ provided by the user 'Rajneesh' ( https://stackoverflow.com/u/10004893/ ) 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 get unique array from nested object with lodash

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 Get a Unique Array from a Nested Object in JavaScript with Lodash

In the world of JavaScript, working with nested objects can often be challenging, especially when faced with the task of extracting unique data. For instance, suppose you're provided with an array of objects, each containing further objects within them, and you need to derive a unique list from those inner objects. This post will guide you through the process of achieving this using both lodash and vanilla JavaScript methods.

The Problem

Consider the following example where we have a collection of objects resembling operation levels, each containing an array of operations with associated names and labels:

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

From this data, you might want to create an array that contains unique operation names and labels, resulting in something like this:

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

The Solution

Using Vanilla JavaScript and Map

You can achieve this without using lodash by utilizing JavaScript's native features. Here’s how:

Flatten the Data: Use the flatMap() method to create a single array of operation objects.

Remove Duplicates: Utilize a Map to filter out duplicate entries based on their names and labels.

Here’s the code snippet to accomplish this:

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

Breakdown:

flatMap: This method transforms the array of objects into a single level array containing all operations.

Map: Maps every operation to its name as the key, ensuring that only unique entries remain.

Using Vanilla JavaScript and filter

If you'd prefer not to use Map, you can achieve similar results using the filter() method:

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

Breakdown:

filter: This method checks for the first occurrence of each operation name-label pair, ensuring that only the first instance remains in the result.

Conclusion

In summary, extracting a unique array from a nested object in JavaScript can be effectively handled using both lodash and vanilla methods. By understanding and applying the flatMap, Map, and filter techniques, you can streamline your data handling processes.

So, next time you encounter a nested object with repeating elements, remember these methods and approach the problem with confidence!