-
QUESTION NO: 4
Given:
1. interface Animal {
2.
void soundOff();
3. }
4.
5. class Elephant implements Animal {
6. public void soundOff() {
7. n(
“
Trumpet
”
);
8. }
9. }
10.
11.
class Lion implements Animal {
12.
public void soundOff() {
13. n(
< br>“
Roar
”
);
14. }
15. }
16.
17. class Alpha1 {
18.
static Animal get( String choice ) {
19. if ( IgnoreCase(
“
meat
eater
”
)) {
20.
return new Lion();
21. } else {
22. return new Elephant();
23. }
24. }
25. }
Which compiles?
A. new
Animal().soundOff();
B. Elephant e =
new Alpha1();
C. Lion 1 =
(
“
meat
eater
”
);
D.
√
new Alpha1().get(
“
veggie
”
).soundO
ff();
QUESTION NO: 7
1. class
Super {
2. public float getNum() {
return 3.0f; }
3. }
4.
5. public class Sub extends Super {.
7. }
Which method, placed at
line6, causes compilation to fail?
A.
√
public void getNum() { }
B. public void getNum(double d) { }
C. public float getNum() { return 4.0f;
}
D. public double getNum(float d) {
return 4.0d; }
QUESTION NO:14
Given:
1. public class OuterClass {
2. private double d1 = 1.0;
3. // insert code here
4. }
Which two are valid if inserted at line
3? (Choose two)
A. static class
InnerOne {
public double methoda() {
return d1; }
}
B. static
class InnerOne {
static double
methoda() { return d1; }
}
C.
√
private
class InnerOne {
public double
methoda() { return d1; }
}
D. protected class InnerOne {
static double methoda() { return d1; }
}
E.
√
public abstract class InnerOne {
public
abstract double methoda();
}
QUESTION NO: 16
Given:
1. interface Beta {}
2.
3. class Alpha implements Beta {
4. String testIt() {
5.
return
“
Tested
”
;
6. }
7. }
8.
9. public class Main1 {
10. static Beta getIt() {
11. return new Alpha();
12.
}
13. public static void main( String[]
args ) {
14. Beta b = getIt();
15. n( () );
16. }
17. }
What is the result?
A. Tested
B.
√
Compilation fails.
C. The code runs with no output.
D. An exception is thrown at runtime.
QUESTION NO: 23
Given:
1. // Point X
2. public
class foo {
3. public static void
main(String[] args) throws Exception {
4. riter out = new riter(
5.
new StreamWriter(), true);
6. n(
“
Hello
”
);
7. }
8. }
Which
statement at Point X on line 1 is required to
allow this code to compile?
A.
√
No statement is required.
B. import .*;
C. include .*;
D. import riter;
E. include
riter;
QUESTION NO: 24
Which two
are valid declarations of a float? (Choose two)
A.
√
float f =
1F;
B. float f = 1.0.;
C.
√
float f =
‘
1
’
;
D. float f =
“
1
”
;
E. float f = 1.0d;
QUESTION NO: 27
Exhibit:
1. public class
Mycircle {
2. public double radius;
3. public double diameter;
4.
5. public void
setRadius(double radius)
6. = radius;
7. er= radius * 2;
8. }
9.
10. public double
getRadius() {
11. return radius;
12. }
13. }
Which
statement is true?
A. The Mycircle
class is fully
encapsulated
（完全封装）
.
B.
√
The diameter
of a given MyCircle is guaranteed to be twice its
radius.
C. Lines 6 and 7 should be in a
synchronized block to ensure encapsulation.
D. The radius of a MyCircle object can
be set without affecting its diameter.
QUESTION NO: 4
1. public class Delta {
2.
static boolean foo(char c) {
3. (c);
4. return true;
5. }
6. public static void main( String[]
argv ) {
7. int i =0;
8. for
( foo(
‘
A
’
< br>); foo(
‘
B
’
)&&(i<2); foo(
‘
C
’
)){
9. i++
10. foo(
‘
D
’
);
12. }
13.
}
14. }
What is the result?
ABDCBDCB
QUESTION NO: 6
Given:
1. public class Test
{
2. public static String output
=
””
;
3.
4. public static void foo(int i) {
5. try {
6. if(i==1) {
7. throw new Exception();
8.
}
9. output +=
“
1
”
;
10. }
11. catch(Exception e)
{
12. output +=
“
2
”
;
13. return;
14. }
15. finally {
16. output +=
“
3
”
;
17. }
18. output +=
“
4
”
;
19. }
20.
21.
public static void main(String args[]) {
22. foo(0); 134
23.
foo(1);23
24.
25. }
26. }
What is the value of
the variable output at line 23?
13423
QUESTION NO: 7
Given:
1. public class X {
2.
public static void main(String [] args) {
3. try {
4. badMethod();
5.
(
“
A
”
);
6. }
7. catch (Exception ex)
{
8.
(
“
B
”
);
9. }
10. finally {
11.
(
“
C
”
);
12. }
13.
(
“
D
”
);
14. }
15. public static void
badMethod() {}
17. }
What is
the result?
ACD
QUESTION NO: 10
Given:
11. String a =
“
ABCD
”
;
12. String b = rCase();
13.
e(
‘
a
’
,
‘
d
’
);
14.
e(
‘
b
’
,
‘
c
’
);
15. n(b);
What is the
result?
abcd
问答
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