title: Can we remove only one element on the localStorage
body: <p>I know that we can remove a group of items with the removeItem(key), but can we remove only one of the value inside? By example I have my key "todo", inside there is <code>["test1", "test2", "test3"]</code>, and I want to remove only "test2". How can I do?
  The split function isn't working...
  Thanks for your help.</p>