Database Reference
In-Depth Information
From the home screen, tap the
HitList
icon to bring the app back to the
foreground. The names are still on the screen. What happened?
When you tap the Home button, the app that's currently in the foreground goes to
the background. When this happens, the operating system flash-freezes everything
currently in memory, including the strings in the
names
array. Similarly, when it's
time to wake up and return to the foreground, the operating system restores what
used to be in memory as if you'd never left.
Apple introduced these advances in multitasking back in iOS 4. They create a
seamless experience for iOS users but add a wrinkle to the definition of persistence
for iOS developers. Are the names really persisted?
No, not really. If you had completely killed the app in the fast app switcher or
turned off your phone, those names would be gone. You can verify this, as well.
With the app in the foreground, double tap the Home button to enter the fast app
switcher, like so:
