How to Save an Array of Objects in localStorage Without Errors

Learn how to correctly store an array of objects in localStorage using JavaScript. Avoid common pitfalls and `TypeError` issues when managing data in your web 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 save an array of objects in localStorage? Getting TypeError: push is not a function

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Save an Array of Objects in localStorage Without Errors

Managing data in a web application often involves storing and retrieving information from the browser's storage. One popular method is to use localStorage, which allows you to store data as strings. This method can become confusing, especially when dealing with arrays of objects. In this guide, we will address a common issue faced in this scenario: a TypeError stating "push is not a function." We'll cover the problem, proposed solutions, and tips for effectively working with localStorage.

The Problem: TypeError in localStorage Handling

When trying to save an array of player data (in object format) to localStorage, you may encounter a TypeError on subsequent calls. This error usually occurs because localStorage treats the data as a string. Here’s a summary of the common mishap:

If the data doesn't exist, you initialize it as an empty array.

On later calls, this variable is still a string and not recognized as an array, leading to the "push is not a function" error.

Your code snippet may look like this:

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

The Solution: Properly Managing localStorage Data

To successfully save your rankings and avoid the aforementioned error, you need to implement a few key steps to manage the data correctly:

1. Understand localStorage Limitations

Only Stores Strings: Remember that localStorage can only store string values. When you retrieve objects or arrays, they need to be converted between a string and their original form.

2. Using JSON.stringify and JSON.parse

Storing Data: Before saving any non-string data, make sure to convert it. Use JSON.stringify(data) to convert the object or array to a string.

Retrieving Data: When you retrieve data stored in localStorage, it will be a string. Use JSON.parse(data) to convert it back to its original format.

3. Revised Code Example

Here’s how you can refactor your code to properly manage the array of player objects:

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

Conclusion

Successfully managing an array of objects in localStorage involves understanding how to properly serialize and deserialize data. Remember that localStorage only stores strings, which requires utilizing JSON.stringify() when saving data and JSON.parse() when retrieving it. By following these guidelines, you can efficiently manage player rankings or any other data structures in your web applications without running into those pesky errors. Happy coding!