Hackforge Academy

Category: React • Beginner

Published on 14 Feb 2026

Explanation

Why localStorage and sessionStorage in JavaScript? In JavaScript, localStorage and sessionStorage are part of the Web Storage API. They are used to: Store data in the browser Save user data without a database Keep data even after page refresh

Code Example

Explanation

Why Do We Need Them? let name = "Praveen"; If page refreshes → data is lost To persist data in browser → we use: 1.localStorage 2.sessionStorage

Code Example

Explanation

LocalStorage Example #white-Store Data: localStorage.setItem("username", "hackforge"); #white-GetData localStorage.getItem("username"); #white-Remove Data localStorage.removeItem("username") #white-Clear All localStorage.clear();

Code Example

Explanation

How to store Dark Mode Toogle using LocalStorage:

Code Example

localStorage.setItem("theme", 
"dark");

// Get theme
let theme = localStorage.getItem("theme");

if (theme === "dark") {
  document.body.style.
backgroundColor = "black";
}

Explanation

SessionStorage Example #white-Store Data: sessionStorage.setItem("username", "hackforge"); #white-GetData sessionStorage.getItem("username"); #white-Remove Data sessionStorage.removeItem("username") #white-Clear All sessionStorage.clear();

Code Example

Explanation

Login Session with SessionStorage:

Code Example

sessionStorage.setItem("isLoggedIn"
, "true");

if(sessionStorage.getItem("isLoggedIn") 
'=== "true") {

  console.log("User logged in");

}

Explanation

Real-Time Use Cases #white-localStorage 1.Remember dark mode 2.Save cart items 3.Save language preference 4.Remember user settings #white-sessionStorage 1.Store login token 2.OTP verification session 3.Temporary form data

Code Example