Answers CHAPTER 15 579
Answers
This section contains the answers to the lesson review questions in this chapter.Lesson 1
- Correct answer: D
A. Incorrect: The use of a different host (www2 instead of www) disallows this URL
from access.
B. Incorrect: The port number must match the origin port nmber.
C. Incorrect: Matching protocols must be used. In this answer, https is used rather
than http.
D. Correct: Because this example uses the same origin, it will have access to the same
data storage space.
E. Incorrect: This example does not have a matching host and would not be allowed
access. - Correct answer: B
A. Incorrect: The cookie value limit is 4 KB.
B. Correct: The recommended limit is 5 MB, although the browser vendor can deter-
mine the respective limits.
C. Incorrect: If websites could store 500 MB of data on the client machine, drastic
performance degradation would result.
D. Incorrect: Internet Explorer supports 10 MB, but that’s not the recommended limit. - Correct answer: A
A. Correct: The clear() method removes all existing key/value pairs existing for the
origin.
B. Incorrect: The removeAll() method does not exist.
C. Incorrect: The abandon() method does not exist.
D. Incorrect: The reset() method does not exist. - Correct answer: A
A. Correct: Nearly all modern browsers support web storage (localStorage and
sessionStorage).
B. Incorrect: Some popular browsers (namely Chrome and Safari) support Web SQL,
but neither Internet Explorer nor Firefox supports it yet.
C. Incorrect: Although IndexDB seems to be gaining support ahead of Web SQL, it is
yet to be adopted by Safari or some of the major mobile browsers.
D. Incorrect: With only Chrome as its strongest supporter, FileSystem API is the least
adoption option.