Oracle 1z0-808 問題集

質問 1：
Which three statements are true about the structure of a Java class?
A. A class can have overloaded static methods.
B. A public class must have a main method.
C. A class can have only one private constructor.
D. The fields need not be initialized before use.
E. A method can have the same name as a field.
F. The methods are mandatory components of a class.
正解：A,D,E

質問 2：
Given the code fragment:

Which modification enables the code to print 54321?
A. Replace line 6 with System.out.print (--x);
B. Replace line 12 with return (x > 0) ? false : true;
C. Replace line 5 with while (is Available(--x)) {
D. At line 7, insert x --;
正解：C

質問 3：
Given the code fragment:

What is the result?
A. A NullPointerException is thrown at runtime.
B. Null element 0
Null element 1
C. Null
Null
D. Element 0
Element 1
正解：A

質問 4：
Given:

What is the result?
A.

B.

C.

D.

正解：A
解説: (Topexam メンバーにのみ表示されます)

質問 5：
Given:

What is the result?
A. 10 : 22 : 22
B. 10 : 22 : 6
C. 10 : 22 : 20
D. 10 : 30 : 6
正解：A

質問 6：
Given:

And given the code fragment:

What is the result?
A. Compilation fails only at line n1
B. Null 0 Auto
4W 150 Manual
C. 4W 100 Auto
4W 150 Manual
D. Compilation fails only at line n2
E. Compilation fails at both line n1 and line n2
正解：E
解説: (Topexam メンバーにのみ表示されます)

質問 7：
Given:

What is the result?
A. Base
DerivedB
B. Base
DerivedA
C. DerivedB
DerivedA
D. DerivedB
DerivedB
E. A classcast Except ion is thrown at runtime.
正解：D

質問 8：
Which two actions will improve the encapsulation of a class?
A. Returning a copy of the contents of an array or ArrayList instead of a direct reference
B. Changing the access modifier of a field from public to private
C. Removing the public modifier from a class declaration
D. Changing the return type of a method to void
正解：A,B

質問 9：
Given:
MainTest.java:

and commands:

What is the result?
A. String main 1 2 3
B. String main 1
C. String main 123
D. An exception is thrown at runtime
正解：B