Oracle 1Z0-815 問題集

質問 1：
Which describes an aspect of Java that contributes to high performance?
A. Java prioritizes garbage collection.
B. Java monitors and optimizes code that is frequently executed.
C. Java has a library of built-in functions that can be used to enable pipeline burst execution.
D. Java automatically parallelizes code execution.
正解：A
解説: (Topexam メンバーにのみ表示されます)

質問 2：
Which three statements are benefits of encapsulation?
A. enables multiple instances of the same class to be created safely
B. protects confidential data from leaking out of the objects
C. enables the class implementation to protect its invariants
D. prevents code from causing exceptions
E. allows a class implementation to change without changing t he clients
F. permits classes to be combined into the same package
正解：B,C,E

質問 3：
Given:

executed with this command:
java Main one two three
What is the output of this class?
A. nothing
B. A java.lang.ArrayIndexOutOfBoundsException is thrown.
C. 1) one
2) two
3) three
D. 1) one
E. The compilation fails.
正解：C

質問 4：
Given:

Which two lines cause compilation errors? (Choose two.)
A. line 6
B. line 7
C. line 12
D. line 8
E. line 9
正解：B,C

質問 5：
Given:

Assuming that this code compiles correctly, which three statements are true? (Choose three.)
A. B is a subtype of A.
B. B cannot be final.
C. A cannot be final.
D. B cannot be abstract.
E. A cannot be abstract.
F. A is a subtype of B.
正解：C,D,F

質問 6：
Which two statements are true for a two-dimensional array?
A. Using a row by column convention, each row of a two-dimensional array must be of the same size
B. At declaration time, the number of elements of the array in each dimension must be specified
C. It is implemented as an array of the specified element type.
D. All methods of the class Object may be invoked on the two-dimensional array.
正解：C,D

質問 7：
Given:

executed using this command:
java Myclass My Car is red
What is the output of this class?
A. java--Myclass--My
B. Myclass--Car--red
C. My--is--java
D. My--Car--is
E. Car--red--My
正解：D

質問 8：
A method is declared to take three arguments.
A program calls this method and passes only two arguments.
What is the results?
A. The third argument is given the value void.
B. Compilation fails.
C. The third argument is given the value zero.
D. The third argument is given the value null.
E. The third argument is given the appropriate falsy value for its declared type.
F. An exception occurs when the method attempts to access the third argument.
正解：B

質問 9：
A method is declared to take three arguments.
A program calls this method and passes only two arguments.
What is the results?
A. The third argument is given the value void.
B. Compilation fails.
C. The third argument is given the value zero.
D. The third argument is given the value null.
E. The third argument is given the appropriate falsy value for its declared type.
F. An exception occurs when the method attempts to access the third argument.
正解：B