Challenge 3 — Solution

Task: Write functions saveTodos(todos) and loadTodos() using the
save/load pattern from this chapter, where todos is an array of
strings. saveTodos should stringify and store the array; loadTodos
should return the parsed array, or an empty array [] (not null) if
nothing has been saved yet. Save 3 todos, then load and log them.

function saveTodos(todos) {
    localStorage.setItem("todos", JSON.stringify(todos));
}

function loadTodos() {
    const stored = localStorage.getItem("todos");
    return stored ? JSON.parse(stored) : [];
}

saveTodos(["Buy milk", "Walk the dog", "Write JS notes"]);

const todos = loadTodos();
console.log(todos);


Expected output:

["Buy milk", "Walk the dog", "Write JS notes"]


Notes:
- The ternary (stored ? JSON.parse(stored) : []) means loadTodos()
  is always safe to call, even before saveTodos has ever run — it
  returns a real, usable empty array instead of null, so code like
  loadTodos().length never crashes.
- Returning [] instead of null specifically means calling code never
  needs an extra null-check before treating the result as an array —
  array methods like forEach/map (Fundamentals Chapter 6) work
  immediately either way.
- saveTodos and loadTodos together hide the JSON.stringify/parse and
  localStorage details entirely — calling code only ever deals with
  a plain array of strings.