How to Update Only One Key in a JSON File Using Node.js

---

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---

The Problem

For instance, consider the following JSON data representation that keeps track of different game modes:

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

Your goal is to update one of these statuses through an API post request, preserving the other data in the file.

The Solution

Below is a step-by-step guide to updating just one key in your JSON file without affecting the other keys.

You'll need to have the necessary modules installed to work on your API. Make sure to require the necessary libraries: fs for file handling, express for handling HTTP requests, and body-parser for parsing incoming requests.

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

Step 2: Fetch and Parse the Existing JSON File

The following code will read the existing JSON data and parse it into a JavaScript object:

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

Step 3: Update the Desired Key

You'll receive the new key and value from the POST request. You need to update the existing object (srcObj) with this new value like so:

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

Step 4: Write the Updated Data Back to the JSON File

After updating the key, convert the JavaScript object back to a JSON string and write it back to the file:

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

Complete Code Example

Here’s how your complete server code would look:

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

Conclusion

This approach minimizes potential errors and keeps your application running smoothly. So, whether you're developing a simple API for your Minecraft server or a larger application, remember these key practices for working with JSON files!

Happy coding!