Answers for "how to save data in local storage and use it"

js save local storage

//Set item
localStorage.setItem('myCat', 'Tom');
//Get item
var cat = localStorage.getItem("myCat");
//Remove item
localStorage.removeItem("lastname");
//Remove all items
localStorage.clear();

save data to local storage

//useEffect(function (){}, []) this hook takes function as its first argument and an array/dependency as 
//which if the [] arrray is empty it runs once, meaning on initial render
useEffect(() => {
  const previousData = JSON.parse(localStorage.getItem("Todos"));
  setTodos(previousData);
},[])
//and if something changes in the dependency's value in this case inputText the function that is passed as the first argument runs each time
useEffect(() => {
 localStorage.setItem('Todos', JSON.stringify(Todos));
}, [inputText])