7. What is the difference between
a Map and a Hashmap?
Map is an interface and a Hashmap
is the implementation of that
interface.
8. What is the difference between
a Hashmap and a Hashtable?
Hashmap is unsynchronized and
permits nulls, HashMap allows null values as key. HashMap does not
guarantee that the order of the map will remain constant over
time
HashMap is non-synchronized and
Hashtable is synchronized
9. Why is Java called a portable
language?
Java program created on Windows
can be executed on Unix and it will work just the
same.
11. What distinguishes "good
architecture" from "bad architecture"?
This is an open-ended question.
There are few aspects of "good" architecture:
- Shall be well structured
(support multiple tiers, parallel development etc.)
- Shall be detailed enough to
share with different levels of organizational structure (marketing,
sales, development, management)
- Shall address functional product
requirements
- Shall address non-functional
product requirements, such as performance, scalability, reliability,
fault tolerance, availability, maintainability, extensibility
- Shall be simple and
comprehendible (to support maintainability and extensibility)
"Bad" architecture is basically
opposite to "good"
architecture.