How to Get Unique Objects from an Array in JavaScript using Set

Learn how to efficiently display unique objects from an array in your JavaScript web app. Discover the power of `Set` to easily generate random, non-repeating items from your data.
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How to Get Unique Objects from an Array in JavaScript

When developing JavaScript applications, you might often encounter scenarios where you need to select a set of random objects from a larger array. This simple requirement can become tricky, especially when you want to ensure that no object is displayed more than once.

In this post, we’ll guide you through a robust solution to displaying unique objects from your array, ensuring you avoid duplicates every time you run your code.

The Problem

Imagine you have a large array of objects, similar to the following structure:

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

In this example, you have an array of objects that you want to display only five at random. While the initial attempt includes an approach that uses sorting with randomness and splicing, it can lead to the same object appearing multiple times.

The Solution: Using Set for Unique Random Objects

To tackle this challenge, we can create unique random indices and use these indices to pull corresponding objects from the original array. Here's how you can implement this solution step-by-step:

1. Define a Function

You'll need to define a function that accepts the original array and the number of unique objects you want to retrieve.

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

2. Explanation of Code

Step 2: Use a Set
The Set data structure automatically controls duplicates. When adding numbers to the set, it will only keep unique values.

Step 3: Generate Random Indices
We use a while loop to continuously generate random indices until we have as many unique ones as required (in this case, the specified number of objects).

Step 4: Retrieve Objects
Finally, we convert the Set back into an array and map each index to the corresponding object in the original array.

3. Using the Function

You can utilize the function as follows:

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

This call will return up to 5 unique objects from your original arr without any duplicates.

Conclusion

This simple approach allows you to efficiently select unique objects from an array in JavaScript. With the power of Set, you can avoid duplicates and ensure a seamless experience in your web application. Remember, this method can be adjusted based on the size of your array and the number of objects you wish to display.

Now, whenever you need to display random objects from a larger array without repeating them, just call getNRandomObjects and you're good to go!

Happy coding!