JavaScript localStorage

JavaScript localStorage is a web storage mechanism that allows you to store key-value pairs locally in the user’s web browser. It provides a way to persistently store data on the client-side, even after the browser is closed and reopened.

Here’s an overview of how to use localStorage in JavaScript:

1. Storing Data:
   To store data in localStorage, you can use the setItem() method. It takes two parameters: a key and a value.

localStorage.setItem('key', 'value');

2. Retrieving Data:
   To retrieve data from localStorage, you can use the getItem() method. It takes the key as a parameter and returns the corresponding value.

const value = localStorage.getItem('key');

3. Updating Data:
   To update the value of a stored item in localStorage, you can simply call setItem() again with the same key.

localStorage.setItem('key', 'new value');

4. Removing Data:
   To remove an item from localStorage, you can use the removeItem() method. It takes the key as a parameter.

localStorage.removeItem('key');

5. Clearing Data:
   To remove all items from localStorage, you can use the clear() method.

localStorage.clear();

6. Checking for Item Existence:
   You can check if a specific item exists in localStorage by using the getItem() method and checking if the returned value is not null.

const exists = localStorage.getItem('key') !== null;

It’s important to note that the data stored in localStorage is persistent and will remain available even after the browser is closed and reopened. However, it is limited to the specific domain and protocol of the web page.

Also, keep in mind that the data stored in localStorage is accessible to JavaScript code running in the same domain, so avoid storing sensitive or confidential information in localStorage.