localstorage alternative for firefox reactjs code example

Example 1: get localstorage

function get(){
    var getJson = localStorage.getItem('key')
    if(getJson){
        arrayName = JSON.parse(getJson)
    }
}

Example 2: local storage javascript

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