Скачать или смотреть Comparing Two Arrays of Objects in JavaScript: Create a New Array with Matching Conditions

Learn how to compare two arrays of objects in JavaScript and create a new array based on matching criteria. Perfect for Node.js developers!
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Comparing Two Arrays of Objects in JavaScript

In the world of JavaScript, it's common to work with arrays of objects. However, there are times when you might need to compare these arrays and create a new array based on specific conditions. A typical scenario would involve two arrays: a parent array and a child array, where you want to match objects based on a common identifier, such as phaseID.

In this guide, we'll explore how to compare two arrays of objects and generate a new array when the phaseID of the parent array matches the phaseID of the child array. We'll break down the solution step-by-step with clear instructions and code examples.

Problem Statement

Imagine you have two arrays defined as follows:

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

The goal is to create a new array that combines these objects in a meaningful way. When phaseID matches between the two arrays, we want to include the child object as part of the corresponding parent object.

Expected Output

The expected format for the new array newArr should look like this:

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

Solution Approach

We will implement this using a simple function that iterates over the parentArr and for each parent object, checks if there are any matching child objects in childArr. Here’s how you can achieve that:

Step-by-Step Explanation

Initialize an Empty Result Array: We will start by creating an empty array that will hold our final merged objects.

Iterate Through the Parent Array: For each object in the parent array, we will create a shallow copy of that object.

Check for Matching Child Objects: For each child in the child array, check if the phaseID matches the phaseID of the current parent object.

Construct Child Nodes Array: If there is a match, add the child object (without phaseID) to a new key called childNode within the parent object. If no matches are found, simply return the parent object as is.

Push Parent Object to Result Array: Finally, add the processed parent object to the result array.

The Code

Here's how the complete function looks in JavaScript:

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

Conclusion

By following the steps outlined above, you should now be able to compare two arrays of objects in JavaScript effectively and create a new array based on matching conditions. This technique is particularly useful for organizing related data and presenting it in a clear and concise structure.

Feel free to test this code, modify the arrays, and watch how changes can affect the output. Happy coding!