580 CHAPTER 15 Local data with web storage
- Correct answer: D
A. Incorrect: Web storage does not support indexing.
B. Incorrect: Web storage does not support transactions.
C. Incorrect: Web storage does not support asynchronous processing.
D. Correct: The simple key/value pair storage’s easy-to-use interface is perhaps the
best feature of web storage.
Lesson 2
- Correct answer: C
A. Incorrect: Storage events have an oldValue property that contains original values
when an entry is updated or removed.
B. Incorrect: Storage events have a key property that contains the name of the entry
being added, updated, or deleted.
C. Correct: There is no property on storage events called changeType.
D. Incorrect: Storage events have a storageArea property that contains either the
localStorage or sessionStorage collection that was changed. - Correct answer: C
A. Incorrect: Session storage events do not go beyond the active tab; other tabs
would not be notified when changes occur.
B. Incorrect: Session storage events do not reach outside their current window.
C. Correct: In this case, an iframe could receive change notifications.
D. Incorrect: Session storage events do not go beyond the active tab; the operating
system would not be notified when changes occur. - Correct answer: D
A. Incorrect: The event.returnValue = false; method is a fairly common way to cancel
many events after they start, but storage events cannot be canceled.
B. Incorrect: The event.preventDefault(); method is another way to cancel many
types of events, but storage events cannot be canceled.
C. Incorrect: Storage events do not bubble up, so the event.stopPropagation();
method would have no effect.
D. Correct: Storage events cannot be canceled after they have been triggered.