What is localStorage?

#webdev #javascript #codenewbie #programming

Local Storage let us save the data which is stored in the browser even when a user refreshes or closes a page. Let's know more about what is Local Storage in JavaScript.

Local Storage holds 2 - 100MB+ data. Saved all data in string(JSON) format. It is also useful for web interface data. It is also used for offline storage of data.

It has 3 three types of methods

Read Data
Write Data
Delete Data

Methods

setItem(k,v) - Add key and value to local storage
getItem(k) - Retrieve a value by the key
removeItem(k) - Remove an item by key
clear() - Clear all storage

setItem()

let itemsArray = {
   id: "OWUAIJFNSOTEKSMJUFTHDSUQ", 
   name: "Rahul"
 }
 localStorage.setItem('items', JSON.stringify(itemsArray));

getItem()

const data = JSON.parse(localStorage.getItem('items')); 
console.log(data);

Note: JSON.parse() is used to covert the contents of localStorage back into something which we can work with later in the data variable.

removeItem()

When passed a key name, the removeItem() method will remove that key from the storage if it exists. If there is no item associated with the given key, this method will do nothing.

localStorage.removeItem('items');

clear()

This method, when invoked, clears the entire storage of all records for that domain. It does not receive any parameters.

localStorage.clear();

Limitations

Do not store sensitive user information in localStorage.
It is not a substitute for a server-based database as information is only stored on the browser.
localStorage is limited to 5MB across all major browsers.
localStorage is quite insecure as it has no forms of data protection and can be accessed by any code on your web page.
localStorage is synchronous, meaning each operation called would only execute one after the other.

Originally at => https://rahulism.tech/article/complete-guide-to-local-storage/

😀Thanks For Reading | Happy Coding😎

Top comments (6)

CBoton • Mar 22 '21

This is helpful for me right now, I'm doing a MERN stack e-commerce site course from Udemy and one of the big complaints I've read is how the instructor stores user data in local storage. My only complaint is that you have a pizza icon with your "buy me a coffee" but other than that thanks for the post.