Challenge 1 — Solution

Task: Save the string "dark" under the key "theme" using
localStorage.setItem. Read it back with getItem and log it. Then
use removeItem to delete it, and log getItem("theme") again to
confirm it now returns null.

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

console.log(localStorage.getItem("theme"));

localStorage.removeItem("theme");

console.log(localStorage.getItem("theme"));


Expected output:

dark
null


Notes:
- setItem always converts its value to a string internally — "dark"
  was already a string here, so nothing changes in this case, but
  it's worth remembering for numbers/booleans/objects.
- getItem returns exactly null (not undefined, not an empty string)
  for a key that doesn't exist — this is the value worth checking
  for before trying to use or parse stored data.
- removeItem only deletes the one named key — any other keys
  previously stored in localStorage are left untouched.