Data Structures - Java 6 - page 239

2. A vector is created, and three strings called Tinker , Evers , and Chance are added
to it. The method removeElement(“Evers”) is called. Which of the following
Vector methods retrieve the string “Chance” ?
a. get(1);
b. get(2);
c. get(“Chance”);
3. Which of these classes implements the Map interface?
a. Stack
b. Hashtable
c. BitSet

8

Answers
1. c. In past versions of Java, to store primitive types such as int in a table, objects
must be used to represent their values (such as Integer for integers). This isn't
true in Java 6: Primitive types are converted automatically to the corresponding
object class through a process called autoboxing.
2. a. The index numbers of each item in a vector can change as items are added or
removed. Because “Chance” becomes the second item in the vector after “Evers” is
removed, it is retrieved by calling get(1) .
3. b.

Certification Practice
The following question is the kind of thing you could expect to be asked on a Java pro-
gramming certification test. Answer it without looking at today's material or using the
Java compiler to test the code.

Given:

public class Recursion {
public int dex = -1;

public Recursion() {
dex = getValue(17);

}

public int getValue(int dexValue) {
if (dexValue > 100)
return dexValue;

else