Oracle 1Z0-815 問題集

質問 1：
Given the code fragment:

What is the result?
A. true false false
B. false false true
C. false true true
D. false true false
正解：D
解説: (Topexam メンバーにのみ表示されます)

質問 2：
Given:
Automobile.java

Car.java

What must you do so that the code prints 4?
A. Remove the parameter from wheels method in line 3.
B. Replace the code in line 2 with Car ob = new Car();
C. Add @Override annotation in line 2.
D. Remove abstract keyword in line 1.
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 3：
Given:

What is the result?
A. [0,0] = Red
[0,1] = White
[1,0] = Black
[2,0] = Blue
[2,1] = Yellow
[2,2] = Green
[2,3] = Violet
B. [0,0] = Red
[0,1] = White
[1,0] = Black
[1,1] = Blue
[2,0] = Yellow
[2,1] = Green
[3,0] = Violet
C. [0,0] = Red
[1,0] = Black
[2,0] = Blue
D. java.lang.ArrayIndexOutOfBoundsException thrown
正解：A
解説: (Topexam メンバーにのみ表示されます)

質問 4：
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 5：
What is the result?
public class StringReplace {
public static void main(String[] args) {
String message = "Hi everyone!";
System.out.println("message = " + message.replace("e", "X")); } }
A. message = Hi Xveryone!
B. message = Hi XvXryonX!
C. message = Hi everyone!
D. A compile time error is produced.
E. message =
F. A runtime error is produced.
正解：B

質問 6：
Given:

Which statement is true?
A. Class Tester does not need to import java.time.LocalDate because it is already visible to members of the package test.
B. All classes from the package java.time. are loaded for the class Diary.
C. Only LocalDate class from java.time package is loaded.
D. Tester must import java.time.LocalDate in order to compile.
正解：A

質問 7：
Given the code fragment:

Which three code fragments can be independently inserted at line nl to enable the code to print one?
A. Long x = 1;
B. Byte x = 1;
C. Integer x = new Integer ("1");
D. Double x = 1;
E. short x = 1;
F. String x = "1";
正解：B,C,E

質問 8：
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 9：
Given the code fragment:
1. ArrayList<Integer> list = new ArrayList<>(1);
2. list.add(1001);
3. list.add(1002);
4. System.out.println(list.get(list.size()));
What is the result?
A. An exception is thrown at run time due to error on line 4
B. Compilation fails due to an error on line 1.
C. 1002
D. An exception is thrown at run time due to error on line 3
正解：A
解説: (Topexam メンバーにのみ表示されます)