When the user closes and reopens the app, the user sees an empty list of scans. We can make the list persistent by saving it after a scan and loading it when the app starts. We can use the application-settings module to store the scans. The storage is based on key-value: a value is assigned to a specific key.

Only booleans, numbers, and strings can be stored using this module. An array cannot be stored. Instead, one could store the length under one key (for instance, items-length) and the items under a set of keys (items-0, items-1, ...). An easier approach is to convert the array to a string using JSON.

The list can be saved using the following function:

function save() { 
  applicationSettings.setString("items", JSON.stringify(items)); 
} 

The Date objects are converted to strings by JSON.stringify. Thus, we must convert them back to a Date object manually:

function load() { 
  const data = applicationSettings.getString("items"); 
  if (data...