Скачать или смотреть How to Add an Object to an Existing Array of Objects in JavaScript

Learn how to efficiently combine objects from two arrays in JavaScript to manage your data seamlessly.
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How to Add an Object to an Existing Array of Objects in JavaScript

When working with arrays of objects in JavaScript, you may encounter the need to combine data from multiple sources based on specific criteria. In this guide, we'll address a common problem: how to add an object from a new array to an existing array of objects, specifically when those objects share the same key.

The Challenge

Consider a scenario where you have an existing array called Grouped, which contains multiple objects. Each object represents a category, having a name and a list of items within that category. You also have another array, newList, which contains new items you want to add to the Grouped array:

Grouped Array: This array includes categories like “Spices” and “Dairy and Eggs”.

New List: This array has new items meant for these categories, such as "whipped cream" and "mushrooms".

You want to merge the newList into the Grouped array, ensuring that items from newList are added to the correct category without losing existing data.

The Solution

To solve this problem, we can follow a structured approach. Here’s how to effectively merge the new items into the existing groups:

Step 1: Initial Setup

First, here are the variables we'll be working with:

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

Step 2: Create a Copy of the Grouped Array

To avoid directly manipulating the original array, create a deep copy of it:

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

Step 3: Loop Through the New List

Use a loop to go through each item in the newList. For each item:

Check if a category already exists in the mergedList.

If it exists, append the new item's data to this group's existing data.

If it doesn't exist, push the entire item into the mergedList.

Here is the code that accomplishes this:

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

Step 4: Output the Merged Array

Finally, you can log the merged list to see the result:

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

Resulting Output

Running the above code will yield the following merged output:

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

Conclusion

Merging arrays of objects in JavaScript can be straightforward when you break it down into manageable steps. By systematically checking for existing categories and appending new items, you can maintain a well-structured dataset. Remember to keep your logic clear and consider making a copy of the initial array to avoid side effects.

With this approach, you can easily manage and manipulate arrays of objects to fit your needs. Happy coding!