Oracle 1Z0-851 問題集

質問 1：
Given:
10.class One {
11.void foo() { }
12.}
13.class Two extends One {
14.//insert method here
15.}
Which three methods, inserted individually at line 14, will correctly complete class Two? (Choose three.)
A. private void foo() { /* more code here */ }
B. int foo() { /* more code here */ }
C. protected void foo() { /* more code here */ }
D. public void foo() { /* more code here */ }
E. void foo() { /* more code here */ }
正解：C,D,E

質問 2：
Given:
1.public class Threads5 {
2.public static void main (String[] args) {
3.new Thread(new Runnable() {
4.public void run() {
5.System.out.print("bar");
6.}}).start();
7.}
8.}
What is the result?
A. The code executes normally and prints "bar".
B. An exception is thrown at runtime.
C. Compilation fails.
D. The code executes normally, but nothing prints.
正解：A

質問 3：
Given:
12.Date date = new Date();
13.df.setLocale(Locale.ITALY);
14.String s = df.format(date);
The variable df is an object of type DateFormat that has been initialized in line 11. What is the result if this code is run on December 14, 2000?
A. The value of s is 14-dic-2000.
B. Compilation fails because of an error in line 13.
C. The value of s is Dec 14, 2000.
D. An exception is thrown at runtime.
正解：B

質問 4：
Given:
11.public static void main(String[] args) {
12.try {
13.args = null;
14.args[0] = "test";
15.System.out.println(args[0]);
16.} catch (Exception ex) {
17.System.out.println("Exception");
18.} catch (NullPointerException npe) {
19.System.out.println("NullPointerException");
20.}
21.}
What is the result?
A. NullPointerException
B. test
C. Compilation fails.
D. Exception
正解：C

質問 5：
DRAG DROP
Click the Task button.

正解：


質問 6：
Given:
5.class Atom {
6.Atom() { System.out.print("atom "); }
7.}
8.class Rock extends Atom {
9.Rock(String type) { System.out.print(type); }
10.}
11.public class Mountain extends Rock {
12.Mountain() {
13.super("granite ");
14.new Rock("granite ");
15.}
16.public static void main(String[] a) { new Mountain(); }
17.}
What is the result?
A. atom granite atom granite
B. An exception is thrown at runtime.
C. Compilation fails.
D. granite granite
E. atom granite
F. atom granite granite
正解：A

質問 7：
Given:
11.String test = "Test A. Test B. Test C.";
12.// insert code here
13.String[] result = test.split(regex);
Which regular expression, inserted at line 12, correctly splits test into "Test A", "Test B", and "Test C"?
A. String regex = "\\w[ \.] +";
B. String regex = "\\s";
C. String regex = " ";
D. String regex = ".*";
E. String regex = "";
F. String regex = "\\.\\s*";
正解：F

質問 8：
Given:
11.class Snoochy {
12.Boochy booch;
13.public Snoochy() { booch = new Boochy(this); }
14.}
15.16.
class Boochy {
17.Snoochy snooch;
18.public Boochy(Snoochy s) { snooch = s; }
19.} And the statements:
21.public static void main(String[] args) {
22.Snoochy snoog = new Snoochy();
23.snoog = null;
24.// more code here
25.}
Which statement is true about the objects referenced by snoog, snooch, and booch immediately after line 23 executes?
A. None of these objects are eligible for garbage collection.
B. Only the object referenced by snooch is eligible for garbage collection.
C. Only the object referenced by booch is eligible for garbage collection.
D. The objects referenced by snooch and booch are eligible for garbage collection.
E. Only the object referenced by snoog is eligible for garbage collection.
正解：D