How to Simultaneously Update Multiple Object Values Inside an Array in JavaScript

Learn how to effectively manage state in JavaScript and React by simultaneously updating multiple object values within an array. This guide provides a clear step-by-step guide to help you achieve desired functionality in your applications.
---

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 simultaneously update multiple object's values inside an array

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Simultaneously Update Multiple Object Values Inside an Array in JavaScript

Managing state in React can be tricky, especially when you're dealing with arrays and objects. A common challenge is updating values in multiple objects simultaneously based on user interactions, such as clicking radio buttons. In this post, we will solve the problem of updating the values of two objects in an array at the same time when a user selects a different option. Let's break down the problem and find a clear solution.

The Problem

You have an array of objects representing different vehicles, each with its own count (total_no). The goal is to:

Decrement the count of the currently selected vehicle when a user selects it.

Increment the count of the previously selected vehicle when a new selection is made.

Array Structure

Here is the current structure of the array you are working with:

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

Current Code

Your current implementation handles the decrementing of the selected vehicle but does not account for updating the previous selection:

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

The Limitation

While the above code updates the count for the currently selected vehicle, it fails to increment the previous selection's count, which is crucial for achieving the desired functionality.

The Solution

To address this issue, we will separate the counting logic from the state-setting logic. This will allow us to decrement the currently selected vehicle and increment the previously selected vehicle effectively. Here's how to do this step-by-step:

Step 1: Update State Management Logic

Instead of directly modifying the state when a vehicle is selected, we can use a function to calculate the new values without immediately setting them into the state.

Updated Code Example:

Store the currently selected value when a vehicle is chosen.

Use a function to calculate the merged data for the vehicles array.

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

Step 2: Replace Consumers of vehiclesData

Now, instead of directly working with vehiclesData, replace it with the makeMergedData() function wherever you need the updated vehicle counts. This will ensure that both the decrement and increment logic work seamlessly together.

Additional Tip

If vehiclesData is not modified anywhere else, consider whether it is necessary to keep it in the state. This could simplify your code and reduce state-related issues in your application.

Conclusion

Updating multiple object's values in an array simultaneously requires careful management of state in React. By isolating the update logic and using a functional approach to handle your data, you can achieve the desired outcome with ease. Now you can ensure that selecting a new vehicle not only decrements the selected vehicle's count but also increments the count of the previously selected vehicle—creating a more accurate and responsive user experience.

Implementing these strategies will make your code more efficient and easier to manage as your application grows. Happy coding!