JAVA期中试卷(英文)
申论辅导-劳动竞赛方案
Subject
Object-Oriented
Programming
Department
Institute of
Information and Technology
Speciality Computer Science and Technology Grade
2012 Class
Name
ID Teacher Director
Topic
Score
Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ Ⅵ
Total
You can answer the questions on the
paper in Chinese. Please read
the problems
carefully, and give the correct answer in proper
place on
the paper.
Ⅰ. True or
False（
1 point for each. Total 10
points.
）10%
1
2
3
4
5
6
7
8
9
10
1. 1.0 is a possible
output from invoking (). [ ]
2. Every
element in an array has the same type. [ ]
3. When invoking a constructor from a
subclass, its superclass’s no-arg
constructor
is always invoked. [ ]
4. You can only
override accessible instance methods. [ ]
5. You can add any number of components to a
panel or a frame. [ ]
6. You can derive a
class from JButton, JPanel, or JFrame. [ ]
7. There are performance differences between
the following two import
statements:import
nPane; import .*; [ ]
8. A call to a method
with a void return type is always a statement
itself. [ ]
9.
An array is a
primitive type value. [ ]
10.
The
output of the following statement is 11 :n('1' +
1);
[ ]
Ⅱ.Fill in the blanks:
(
1 points for each blank. Total 15
points.
) 15%
1. Declare an int
constant SIZE with value 18 :
1
2. Which of the
following statements are equivalent?
Which ones are correctly indented?
3. In loops the keyword
only ends the current iteration;
The
keyword immediately ends the innermost loop
4.
Evaluate the following method calls:
(a) (25)
(b) (2.5)
(c) (2.5)
(d) (2.5)
5. Object-oriented
programming techniques may include features such
as , ,
,
and .
6. When an array of objects is created, its
elements are assigned the default
value of
.
7.
Three simple and
frequently used layout managers are
,
GridLayout, and BorderLayout.
Ⅲ.
Error Correction (Total 30 points.) 30%
1.
Identify
(标出)
and fix
(修改)
the
errors in the following code: （
14%
）
1 public class Test {
2 public void
main(String[] args) {
3 for (int i = 0; i
< 10; i++);
4 sum += i;
5
6
if (i < j);
7 n(i)
8 else
9 n(j);
2
10
11
while (j < 10);
12 {
13 j++;
14 };
15
16 do {
17
j++;
18 } while (j < 10)
19 }
20
}
2.
Identify and
fix the errors in the following classes:
（
16%
）
1 class Circle {
2 private double radius;
3 public
string color;
4 public Circle (double
radius) {
5 radius = radius;
6
}
7
8 public setRadius(double r) {
9 radius=r;
10 }
11 public
double getRadius() {
12 return radius;
13 }
14
15 public double
getArea() {
16 return radius * radius *
17 }
18 }
19
20 class B
extends Circle {
21 private double length;
22
23 B(double radius, double len) {
24 Circle(radius);
25 length
= len;
3
26 }
27
28 ** Override getArea() *
29
public double getArea() {
30 return
getArea() * length;
31 }
32
}
33 ** test Circle class **
34 public class testCircle (){
35
public static void main(String[] args) {
36
Circle c1=new Circle(1.0);
37 n(c1.
getArea);
38 =2.0
39 =red;
40 n(ng());
41 }
42 }
Ⅳ. Programing
Analysis (
5 point for 25 points.
) 25%
the result of the following programs: ( 10%
)
4
2.
Show the output of the following code: ( 5% )
import .*;
public class Test {
public
static void main(String[] args) {
JButton
jbtOK = new JButton(
n(ble());
JFrame frame
= new JFrame();
n(ble());
}
}
3. Show the output of
following program: ( 10% )
ming (
Total 20 points
) 20%
1.
Design the interface of ATM input keyboard.
You can use the classes
below:
Layout
n
5
6
2.
Design a class named Person
and its two subclasses named Student and
Faculty and Staff subclasses of Employee. A person
has a
name,address, phone number, and email
address. A student has a class
status
(freshman,sophomore, junior, or senior). Define
the status as a
constant. An employee has an
office, salary, and date hired. Define a class
named MyDate that contains the fields year,
month, and day. A faculty member
has office
hours and a rank. A staff member has a title.
Override the toString
method in each class to
display the class name and the person’s name.
Implement the classes. Write a test program
that creates a Person, Student,
Employee,
Faculty, and Staff, and invokes their toString()
methods.
7
8