Oracle 1z0-808 問題集

質問 1：
Given the code from the Greeting.Java file:

Which set of commands prints Hello Duke in the console?

A. Option A
B. Option C
C. Option D
D. Option B
正解：B
解説: (Topexam メンバーにのみ表示されます)

質問 2：
Given the definitions of the Birdclass and the Peacock class:

and the code fragment:

Which code snippet can be inserted to print Fly.Dance. ?
A. Bird p = new Peacock();
B. Bird b = new Peacock ();
Peacock p = (Peacock) b;
C. Peacock b = new Peacock ();
Bird p = (Bird) b;
D. Bird b = new Bird();
Peacock p = (Peacock) b;
正解：D

質問 3：
Given this code for the classes MyException and Test:

What is the result?
A. A
B. B
C. I
D. A compile time error occurs at line n1.
E. AB
正解：C

質問 4：
Given the following four Java file definitions:
// Foo.java
package facades;
public interface Foo { }
// Boo.java
package facades;
public interface Boo extends Foo { }
// Woofy.java
package org.domain
// line n1
public class Woofy implements Boo, Foo { }
// Test.java
package.org;
public class Test {
public static void main(String[] args) {
Foo obj=new Woofy();
Which set modifications enable the code to compile and run?
A. At line n1, Insert: import facades.*;At line n2, insert:import facades.Boo;import org.*;
B. At line n1, Insert: import facades.Foo, Boo;At line n2, insert:import org.domain.Woofy;
C. At line n1, Insert: import facades.*;At line n2, insert:import facades;import org.domain.Woofy;
D. At line n1, Insert: import facades;At line n2, insert:import facades;import org.domain;
E. At line n1, Insert: import facades.*;At line n2, insert:import facades;import org.*;
正解：C

質問 5：
Given:
public class Test {
public static void main(String[] args) {
int ax = 10, az = 30;
int aw = 1, ay = 1;
try {
aw = ax % 2;
ay = az / aw;
} catch (ArithmeticException e1) {
System.out.println("Invalid Divisor");
} catch (Exception e2) {
aw = 1;
System.out.println("Divisor Changed");
}
ay = az /aw; // Line 14
System.out.println("Succesful Division " + ay);
}
}
What is the result?
A. Invalid Divisor
Exception in thread "main" java.lang.ArithmeticException: / by zero at
test.Teagle.main(Teagle.java:14)
Successful Division 1
B. Invalid Divisor
Successful Division 30
C. Invalid Divisor
Exception in thread "main" java.lang.ArithmeticException: / by zero at
test.Teagle.main(Teagle.java:14)
D. Invalid Divisor
Divisor Changed
Successful Division 30
正解：C

質問 6：
Given the for loop construct:
for ( expr1 ; expr2 ; expr3 ) {
statement;
}
Which two statements are true?
A. The expression expr3 must be present.
It is evaluated after each iteration through the loop.
B. When expr2 evaluates to false, the loop terminates.
It is evaluated only after each iteration through the loop.
C. The expression expr1 is optional.
it initializes the loop and is evaluated once, as the loop begin.
D. This is not the only valid for loop construct; there exits another form of for loop constructor.
正解：C,D
解説: (Topexam メンバーにのみ表示されます)

質問 7：
Given the code fragments:

What is the result?
A. Super
Sub
Sub
B. Contract
Contract
Super
C. Compilation fails at line n2
D. Compilation fails at line n1
正解：A

質問 8：
Given:

The class is poorly encapsulated.
You need to change the circle class to compute and return the area instead.
Which three modifications are necessary to ensure that the class is being properly encapsulated?
(Choose 3)
A. Remove the area field.
B. Change the getRadius () method: public double getRadius () { area = Math.PI * radius * radius; return radius; }
C. When the radius is set in the Circle constructor and the setRadius () method, recomputed the area and store it into the area field
D. Change the getArea () method public double getArea () { return area; }
正解：A,C,D

質問 9：
Given:

And given the commands:
javac Test.Java
Java Test Hello
What is the result?
A. Failure
B. Compilation fails.
C. Success
D. An exception is thrown at runtime
正解：A