Скачать или смотреть How to Save Different Objects in One Array in JSON Using Node.js

Learn how to seamlessly save multiple objects in a JSON array using Node.js, ensuring that each submitted form data entry gets added rather than overwriting existing entries.
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Saving Multiple Objects in JSON Using Node.js

When developing web applications, it's common to handle form submissions and store the submitted data for future use. However, if you're storing this data in a JSON file using Node.js, you may find yourself facing a challenge. What happens when a user submits a new form? If you simply write the new data to the file, you may inadvertently overwrite previous submissions.

In this guide, we will explore how to save different objects in one array within a JSON file using Node.js, allowing you to preserve all form submissions without losing any data.

The Problem

In your current setup, you are collecting user data from a simple HTML form that includes fields for the first and last name. After the form is submitted, your Node.js server processes this data and writes it to a JSON file (users.json). However, each new submission replaces the existing data instead of adding it to an array. Here's how your current code looks:

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

This method saves only the latest submission, which is not ideal for keeping track of multiple entries.

The Solution

To address this issue, we need to make a few modifications to your Node.js code, which will ensure that every new submission is added to an array in the JSON file rather than replacing old data. Here's the step-by-step solution:

Step 1: Initialize an Array for Data

Set up a list array that will hold all the data entries from the form. If the JSON file already exists, we will read its contents and parse it.

Step 2: Read Existing Data from JSON

If the JSON file already contains data, we'll read it and convert it from a string back to an array of objects.

Step 3: Add New Data to the Array

For each new submission, we will push the new user data object onto this list array.

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

Finally, we will convert the updated array back into a JSON string and write it to the file, preserving all data entries.

Here's the updated code:

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

Explanation of the Changes

File Existence Check: We first check if the file user_list.json exists. If it does, we read its contents and parse them into our list array.

Pushing New Data: Each new form submission is represented by an object containing the user's first and last name. This object is added to the existing list array.

Writing Back: We overwrite the JSON file with the updated array, which now includes all previous entries along with the new one.

Conclusion

By following these steps, you've effectively modified your Node.js application to support storing multiple submissions in an organized manner. Each time a user submits the form, their data is added to an array in user_list.json, allowing for easy retrieval and management of user information.

Feel free to reach out if you have any questions or further difficulties with your Node.js application!