Question:20
Given a file GrizzlyBear.java:
1. package animals.mammals;
2.
3. public class GrizzlyBear extends Bear {
4. void hunt() {
5. Salmon s = findSalmon();
6. s.consume();
7. }
8. }
and another file, Salmon.java:
1. package animals.fish;
2.
3. public class Salmon extends Fish {
4. void consume() { /* do stuff */ }
5. }
Assume both classes are defined in the correct directories for theft
packages, and that the Mammal class correctly defines the
findSalmon() method. Which two changes allow this code to compile
correctly? (Choose two.)
A. add public to the start of line 4 in Salmon.java
B. add public to the start of line 4 in GrizzlyBear.java
C. add import animals.mammals.*; at line 2 in Salmon.java
D. add import animals.fish.*; at line 2 in GrizzlyBear.java
E. add import animals.fish.Salmon.*; at line 2 in GrizzlyBear.java
F. add import animals.mammals.GrizzlyBear.*;at line 2 in Salmon.java

Answer: AD
21. Which are valid declarations? (Choose all that apply.)
A. int $x;
B. int 123;
C. int _123;
D. int #dim;
E. int %percent;
F. int *divide;
G. int central_sales_region_Summer_2005_gross_sales;

Answer:
-> A, C, and G are legal identifiers.
->   B is incorrect because an identifier can't start with a digit.
       D, E, and F are incorrect because identifiers must start with $, _, or a letter.

22. Which method names follow the JavaBeans standard? (Choose all that apply.)
A. addSize
B. getCust
C. deleteRep
D. isColorado
E. putDimensions

Answer:
-> B and D use the valid prefixes 'get' and 'is'.
->A, C, and E are incorrect because 'add', 'delete' and 'put' are not standard   JavaBeans name prefixes.

23. Given:
1. class Voop {
2. public static void main(String[] args) {
3. doStuff(1);
4. doStuff(1,2);
5. }
6. // insert code here
7. }
Which, inserted independently at line 6, will compile? (Choose all that apply.)
A. static void doStuff(int... doArgs) { }
B. static void doStuff(int[] doArgs) { }
C. static void doStuff(int doArgs...) { }
D. static void doStuff(int... doArgs, int y) { }
E. static void doStuff(int x, int... doArgs) { }

Answer:
-> A and E use valid var-args syntax.
-> B and C are invalid var-arg syntax, and D is invalid because the var-arg must be the last of a method's arguments. (Objective 1.4)

24. Which are legal declarations? (Choose all that apply.)
A. short x [];
B. short [] y;
C. short[5] x2;
D. short z2 [5];
E. short [] z [] [];
F. short [] y2 = [5];

Answer:
-> A, B, and E are correct array declarations; E is a three dimensional array.
-> C, D, and F are incorrect, you can't include the size of your array in a declaration unless you also instantiate the array object. F uses invalid instantiation syntax. (Objective 1.3)