How to create and read from browser storage
Intro
Browser storage, also known as web storage or DOM storage, is a method for storing data in the browser that allows websites to store and access data on the user's device. This is useful for creating a better user experience and allowing websites to work offline. In this article, I will discuss how to create and read from browser storage using the localStorage and sessionStorage objects in JavaScript.
Prerequisites
-
A web browser that supports the localStorage and sessionStorage objects, such as Google Chrome, Mozilla Firefox, or Microsoft Edge. These objects are supported by most modern browsers, but you can check the compatibility of your browser on the Can I Use website (https://caniuse.com/#feat=namevalue-storage).
-
Basic knowledge of HTML, CSS, and JavaScript. You will need to know how to create and edit web pages, as well as how to write and run JavaScript code in the browser.
-
A text editor or integrated development environment (IDE) to write and edit your code. You can use any text editor or IDE that you are comfortable with, such as Visual Studio Code, Sublime Text, or Atom
Saving a value to localStorage
To save a value in local storage, you can use the setItem()
method like this:
localStorage.setItem('key', 'value')
Getting a value from localStorage
var value = localStorage.getItem('key')
Removing a value from localStorage
You can also use the removeItem()
method to remove a value from storage:
localStorage.removeItem('key')
Saving, getting, and deleting a value from sessionStorage
The sessionStorage
object works in the same way, but the data is only stored for the current session and is deleted when the browser is closed.
sessionStorage.setItem('key', 'value')
var value = sessionStorage.getItem('key')
sessionStorage.removeItem('key')
Things to note when working with localStorage and sessionStorage
It's important to note that the values stored in browser storage are always strings, so you may need to convert them to a different data type if necessary.
For example, if you want to store a number, you can use the parseInt()
or parseFloat()
functions to convert the string to a number.
localStorage.setItem('num', '42')
var num = parseInt(localStorage.getItem('num'))
Further reading
Further readign references for the topic of creating and reading from browser storage, you can refer to the official documentation for the localStorage and sessionStorage objects on the Mozilla Developer Network (MDN) website.
Here are the links to the documentation for each object:
- localStorage: https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage
- sessionStorage: https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage
These pages provide detailed information about the methods, properties, and events for each object, as well as examples of how to use them in your code. You can use these references as a reliable source of information when working with browser storage in JavaScript.
Additionally, the World Wide Web Consortium (W3C) also provides a specification for web storage, which you can find here: https://www.w3.org/TR/webstorage/. This specification defines the standard for web storage and provides a detailed description of how it works. You can use this reference as a more technical resource for understanding the underlying concepts and principles of web storage.
Conclusion
Browser storage is a useful tool for storing data on the user's device and improving the user experience of a website. By using the localStorage and sessionStorage objects in JavaScript, you can easily create and read from browser storage. It's important to remember that the values stored in browser storage are always strings, so you may need to convert them to a different data type if necessary. By using these techniques, you can make your website more responsive and effective for your users.