Oracle 1z0-808 問題集

質問 1：
Which two are benefits of polymorphism?
A. More efficient code at runtime
B. Code that is protected from extension by other classes
C. More flexible and reusable code
D. Faster code at runtime
E. More dynamic code at runtime
正解：C,E

質問 2：
Given the code fragment:

What is the result?
A. Invalid calculation
B. Answer = 0
C. Compilation fails only at line n1.
D. Compilation fails at line n1 and line2.
E. Compilation fails only at line n2.
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 3：
Given:
public class SuperTest {
public static void main(String[] args) {
statement1
statement2
statement3
}
}
class Shape {
public Shape() {
System.out.println("Shape: constructor");
}
public void foo() {
System.out.println("Shape: foo");
}
}
class Square extends Shape {
public Square() {
super();
}
public Square(String label) {
System.out.println("Square: constructor");
}
public void foo() {
super.foo();
}
public void foo(String label) {
System.out.println("Square: foo");
}
}
}
}
What should statement1, statement2, and statement3, be respectively, in order to produce the result?
Shape: constructor
Square: foo
Shape: foo
A. Square square = new Square ();
square.foo ();
square.foo(bar);
B. Square square = new Square ();
square.foo ();
square.foo("bar");
C. Square square = new Square ();
square.foo ();
square.foo ();
D. Square square = new Square();
square.foo("bar");
square.foo();
E. Square square = new Square ("bar");
square.foo ("bar");
square.foo();
F. Square square = new Square ("bar");
square.foo ("bar");
square.foo ("bar");
正解：D

質問 4：
Given:
abstract class A1 {
public abstract void m1();
public void m2() { System.out.println("Green"); }
}
abstract class A2 extends A1 {
public abstract void m3();
public void m1() { System.out.println("Cyan"); }
public void m2() { System.out.println("Blue"); }
}
public class A3 extends A2 {
public void m1() { System.out.println("Yellow"); }
public void m2() { System.out.println("Pink"); }
public void m3() { System.out.println("Red"); }
public static void main(String[] args) {
A2 tp = new A3();
tp.m1();
tp.m2();
tp.m3();
}
}
What is the result?
A. Cyan
Green
Red
B. Compilation Fails
C. Yellow
Pink
Red
D. Cyan
Blue
Red
正解：C

質問 5：
Given the following class:

And given the following main method, located in another class:

Which three lines, when inserted independently at line n1, cause the program to print a o balance?
A. acct.changeAmount(-acct.getAmount());
B. amount = 0;
C. acct.changeAmount(0);
D. acct. getAmount () = 0;
E. acct.changeAmount(-acct.amount);
F. acct.amount = 0;
G. this.amount = 0;
H. acct (0) ;
正解：A,E,F
解説: (Topexam メンバーにのみ表示されます)

質問 6：
Given the code fragment:

What is the result?
A. 2014-09-30T00:00:00
B. 2014-07-31T01:01:00
C. An exception is thrown at runtime.
D. 2014-07-31
正解：B

質問 7：
Given the code fragment:

What is the result?
A. 0 Found
B. 3 Found
C. Compilation fails.
D. 1 Found
正解：B

質問 8：
Given the code fragment:
String[] cartoons = {"tom","jerry","micky","tom"};
int counter =0;
if ("tom".equals(cartoons[0])) {
counter++;
} else if ("tom".equals(cartoons[1])) {
counter++;
} else if ("tom".equals(cartoons[2])) {
counter++;
} else if ("tom".equals(cartoons[3])) {
counter++;
}
System.out.print(counter);
What is the result?
A. 0
B. 2
C. 4
D. 1
正解：D
解説: (Topexam メンバーにのみ表示されます)

質問 9：
Given:

and the code fragment:

What is the result?
A. true:false:true
B. true:true:false
C. false:true:false
D. false:true:true
正解：D