1Z0-501問題集、Oracle実際の試験問題

質問 1

CORRECT TEXT
Given:
AnInterface is an interface.
AnAdapter0 is a non-abstract, non-final class with a zero argument constructor.
AnAdapter1 is a non-abstract, non-final class without a zero argument constructor, but with a constructor that takes one int argument.
Which two construct an anonymous inner class? (Choose Two)
F.AnAdapter1 aa=new AnAdapter1(){}
G.AnAdapter0 aa=new AnAdapter0(){}
H.AnAdapter0 aa=new AnAdapter0(5){}
I.AnAdapter1 aa=new AnAdapter1(5){}
J.AnInterface a1=new AnInterface(5){}

正解:

B, D

質問 2

Exhibit:
1 . interface foo {
2 . int k = 0;
3 . ]
4 .
5 . public class test implements Foo (
6 . public static void main(String args[]) (
7 . int i;
8 . Test test = new test ();
9 . i= test.k;
1 0.i= Test.k;
1 1.i= Foo.k;
1 2.)
1 3.)
1 4.
What is the result?

A. An error at line 10 causes compilation to fail.

B. An error at line 11 causes compilation to fail.

C. An error at line 2 causes compilation to fail.

D. An error at line 9 causes compilation to fail.

E. Compilation succeeds.

正解: E

質問 3

Given:
1 . public class Test {
2 . public static void main (String []args){
3 . unsigned byte b = 0;
4 . b--;
5 .
6 .}
7 . }
What is the value of b at line 5?

A. Compilation will fail.

B. 127

C. -1

D. 255

E. Compilation will succeed but the program will throw an exception at line 4.

正解: A

質問 4

Given:
1. class super {
2. public float getNum() {return 3.0f;}
3 . )
4 .
5 . public class Sub extends Super {
6 .
7 .)
Which method, placed at line 6, will cause a compiler error?

A. Public void getNum (double d)
{ }

B. Public void getNum () { }

C. Public double getNum (float d) {retrun 4.0f; }

D. Public float getNum(){return 4.0f; }

正解: B

質問 5

Given:
1 . public class test (
2 . public static void main (String args[]){
3 .int i = 0xFFFFFFF1;
4 .int j = ~i;
5 .
6 .}
7 . )
What is the decimal value of j at line 5?

A. -15

B. An error at line 3 causes compilation to fail.

C. An error at line 4 causes compilation to fail.

D. 14

E. 1

F. 0

正解: D

質問 6

Given:
1 . public class MethodOver {
2 . private int x, y;
3 . private float z;
4 . public void setVar(int a, int b, float c){
5 . x = a;
6 . y = b;
7 . z = c;
8 .}
9 . }
Which two overload the setVar method? (Choose Two)

A. public void setVar(int a, float b){
x = a;
z = b;
}

B. public void setVar(int a, float c, int b) {
this(a, b, c);
}

C. void setVar (int a, int b, float c){
x = a;
y = b;
z = c;
}

D. public void setVar(int a, float c, int b) {
setVar(a, b, c);
}

E. public void setVar(int ax, int by, float cz) {
x = ax;
y = by;
z = cz;
}

正解: A,D

質問 7

Exhibit:
1 . public class Mycircle {
2 . public double radius;
3 . public double diameter;
4 .
5 . public void setRadius(double radius)
6 . this.radius = radius;
7 . this.diameter= radius * 2;
8 .}
9 .
1 0. public double getRadius(){
1 1. return radius;
1 2.}
1 3. }
Which statement is true?

A. The Mycircle class is fully encapsulated.

B. The radius of a MyCircle object can be set without affecting its diameter.

C. Lines 6 and 7 should be in a synchronized block to ensure encapsulation.

D. The diameter of a given MyCircle is guaranteed to be twice its radius.

正解: D

質問 8

Which two interfaces provide the capability to store objects using a key-value pair?
(Choose Two)

A. Java.util.List.

B. Java.util.Set.

C. Java.util.StoredSet.

D. Java.util.StoredMap.

E. Java.util.Collection.

F. Java.util.Map.

正解: D,F

質問 9

The file "file.txt" exists on the file system and contsins ASCII text.
Given:
3 8. try {
3 9. File f = new File("file.txt");
4 0. OutputStream out = new FileOutputStream(f, true);
4 1. }
4 2. catch (IOException){}
What is the result?

A. An exception is thrown because the file is not closed.

B. The code runs and no change is made to the file.

C. The code runs and sets the length of the file to 0.

D. The code runs and deletes the file from the file system.

E. The code does not compile.

正解: E

Oracle Java Certified Programmer - 1Z0-501 模擬練習