how does localstorage work in javascript code example

Example 1: local storage javascript

function createItem() {
	localStorage.setItem('nameOfItem', 'value'); 
} 
createItem() // Creates a item named 'nameOfItem' and stores a value of 'value'

function getValue() {
	return localStorage.getItem('nameOfItem');  
} // Gets the value of 'nameOfItem' and returns it
console.log(getValue()); //'value';

Example 2: local storage javascript

localStorage.setItem('user_name', 'Rohit'); //store a key/value
var retrievedUsername = localStorage.getItem('user_name'); //retrieve the key

Example 3: javascript get local storage

var Item = localStorage.getItem('youritem');

Example 4: javascript localstorage

var KeyName = window.localStorage.key(index);