java考试试卷模拟试卷

华东交通大学软件学院03～04第二学期Java试卷

班级姓名学号

一、选择題（40分）

1、在Java中，哪个修饰符定义的变量可通过类名来访问。

A. public

B. static

C.protected

D.private 2．在浏览器中执行applet 程序，哪个方法最先执行( )。

A. paint ()

B. start()

C. init()

D. repaint()

3、下列关于修饰符混用的说法，错误的是( )

A．abstract不能与final并列修饰同一个类

B．abstract类中不可以有private的成员

C．abstract方法必须在abstract类中

D．static方法中能处理非static的属性

4、以下代码段执行后的输出结果为（）

int x=3； int y=10； System.out.println(y%x);

A. 0

B. 1

C. 2

D. 3

5、Java中，（）类是所有类的最终祖先？

A. String

B. Nuber

C. Lang

D. Object

6、以下标识符中哪项是不合法的( )

A. Great

B. many

C. int

D. _x1

7、 Java语言中，长整数占用的存储字节数是( )。

A. 4

B. 8

C. 16

D.2

8、设有下面两个赋值语句：

a = Integer.parseInt(“1024”);

就是将String字符类型数据转换为Integer整型数据，args[0]就是输入参数中的第一个参数字符串。

b = Integer.valueOf(“1024”) ;

(2)valueOf方法将传入的参数String转化为int型值

下述说法正确的是（）。

A.a是整数类型变量，b是整数类对象。

B.a是整数类对象，b是整数类型变量。

C.a和b都是整数类对象并且它们的值相等。

D.a和b都是整数类型变量并且它们的值相等。

9、若在某一个类定义中定义有如下的方法：abstract void performDial( ); 该方法属于( )。

A. 本地方法

B. 最终方法

C. 静态方法

D. 抽象方法

10、下面哪个包是用于创建图形用户界面的( )。

A. java.applet

B. java.awt

C. https://www.360docs.net/doc/075263528.html,ng

D. java.util

11、通过哪个方法可以改变按钮的颜色

A． setColor B. setBackground

C. getBackground E. setForeground

12、编译和解析执行一个java应用程序应分别采用的命令是（）

A. Java和Javac

B. Javac和Java

C. Javap和Java

D. Javac和Jdb

13、以下程序段：

switch(m) {

case 0: System.out.println("case 0");

case 1: System.out.println("case 1"); break;

case 2:

default: System.out.println("default"); }

m为何值时程序的输出是“default”？

A. 0

B. 1

C. 2

D. 3

14. 定义一个1维整型数组，正确的是：

(A) int a[]= new int [10];

(B) int a[10] = new int [];

(C) int a[10] = new int [10];

(D) int []a = new int [10];

15. 用8进制表达8的值以下哪个正确?

(A) 010 (B)0x10 (C)08 （D）0x8

16. 给出以下程序段：

boolean m = true;

if ( m )

System.out.println("False");

else

System.out.println("True");

则运行结果为：

(A) False (B) True (C) None (D) 运行时出错.

17. 下列哪条指令可用于创建具有10行20列的文本域：

（A）new TextArea(10,20)

（B）new TextArea(20,10)

（C）new TextArea(new Rows(10), new Colums(20)

（D）new TextArea(200)

18. 以下程序段执行时输入：java test

则输出结果为.

class test

{

public static void main(String args[])

{

System.out.println(args[0]);

}

}

(A) 无任何输出.

(B) 产生数组访问越界例外

(C) 输出0

(D) 输出test

19. 新创建的 Frame是不可见的，使用哪个方法可使其可见。

(A) setSize(300,200) (B) setVisible(true)

(C) dispose() (D) repaint()

20. 以下哪个方法用来从字符串中获取一个字符。

（A）indexOf(String str)

（B）substring(int beginIndex, int endIndex)

（C）concat(String str)

（D）charAt(int index)

二、是非题（10分）

1. Java 应用程序可以在浏览器中执行 1

2. 要改变一个字符串的内容可以使用StringBuffer类 1

3．多线程程序必须编写run()方法。 1

4．Socket通信中服务方要创建Socket对象并监听客户连接。1

5．Java程序中可使用throws语句明确抛出例外对象。1

6．Vector对象中可以存储不同类型的对象。 1

7．ItemListener接口定义了itemStateChanged方法。实现该接口的类就要编写该方法的具体实现代码。

8．子类中要访问父类中与子类有相同方法头的方法可使用this来特指。

9. Java Application源程序的主类是指包含有main方法的类。

10．一个Java类只能继承一个父类，但可以实现多个接口。

三、分析下面各程序，写出程序的运行结果。（20分）

(1) public class Ex1{

static int m=2;

public static void main(String args[])

{

Ex1 obj1=new Ex1();

Ex1 obj2=new Ex1();

obj1.m=m+1;

System.out.println(“m=”+obj2.m);

}

}

（2）public class Ex2{

public static void main(String[] args) {

int n0 = 1, n1 = 1, n2;

for(int i = 0; i <4; i++) {

n2 = n1 + n0;

System.out.print(n2 + " ");

n0 = n1;

n1 = n2;

}

System.out.println();

}

}

（3） public class Ex3

{

String name;

int age;

public Ex3(String name,int age)

{

https://www.360docs.net/doc/075263528.html,=name;

this.age=age;

}

void incAge()

{

age=age+1;

}

public static void main(String a[])

{

student x1=new Ex3("张三",20);

student x2=new Ex3("李四",22);

x2.incAge();

System.out.println("name="+https://www.360docs.net/doc/075263528.html,+",age="+x1.age); System.out.println("name="+https://www.360docs.net/doc/075263528.html,+",age="+x2.age); }

}

（4）class Ex4{

public static void main(String args[]){

int[] a={1,2,3};

for (int i=1;i<3;i++) a[i]=a[i-1]+1;

for(int i=0;i<3;i++) System.out.print(a[i]+ " "); }

}

（5）public class Ex5 {

public static void main(String[] args) {

String s = "hello world";

int len = s.length();

StringBuffer rev = new StringBuffer(len);

for (int i = (len - 1); i >= 0; i--) {

rev.append(s.charAt(i));

}

System.out.println(rev.toString());

}

}

四、编程题（30分）

（1）编写一个图形界面程序，实现人民币与欧元的换算，在两个文本框中分别输入人民币数量和汇率，点击“转换”按钮在结果标签中显示欧元值。

（2）编写Java Application，产生100个随机整数给一维数组赋值，输出该数组，每行输出5个元素，然后将其中的素数找出来输出。

（3）编写Applet程序，从Applet参数中获取一个参数转化为整数n，在Applet 中用paint方法显示n的阶乘结果。

2002-2003学年第二学期《Java语言》考试卷

班级学号姓名分数

PART A (70 * 1 = 70 Marks) (Note: Choose the best answer. Write only the answer.)

1. 1. In Java, when a program is compiled, it is converted into ______

a) Machine code b) Byte code

c) Hexadecimal code d) None of the above.

2. 2. The ______ is the mechanism that binds the data and functions together

with each

other and keeps both safe from outside interference.

a) Encapsulation b) Polymorphism c) Inheritance d) None

3. 3. Java programs should be saved with the extension

a) .c b) .txt c) .java d) .doc

4. 4. ______ do not cause the computer to perform any action when the

program is run.

a) Comments b) the keyword Class c) Main method d) None

5. 5. When ________ appears in a string of characters, Java combines the

next

character and forms the escape sequence.

a) front slash ( / ) b) back slash ( \ ) c) comments

d) None

6. 6. Java’s numerous predefined classes are grouped into categories or

related classes

called ______

a) Objects b) Classes c) Library d) Packages

7.7. The name of the package with “java” is called

a) Core packages b) Extension package c) Both a & b

d) None

8.8. The _______ class provides prepackaged dialog boxes that enables us

to display

boxes.

a) JApplet b) Graphics c) Container d) JoptionPane

9.9. The ________ statement is used to include all the necessary classes

into our

program from the specified package.

a) class definition b) import c) main definition d) None

1 10 ._______ is the method which is used to read the value from the user

which comes

under the class JoptionPane.

a) showMessageDialog( ) b) showInputDialog( )

c) System.out d) System.in

1 11.The method which is used to convert the String value to Integer value

a) parseDouble b) parseInt c)parseFloat d)none

12. What will be printed out if you attempt to compile and run the following

code ?

int i=1;

switch (i)

{

case 0:

System.out.println("zero");

break;

case 1:

System.out.println("one");

case 2:

System.out.println("two");

default:

System.out.println("default");

}

1) one

2) one, default

3) one, two, default

4) default

13. int i=9;

switch (i)

{

default:

System.out.println("default");

case 0:

System.out.println("zero");

break;

case 1:

System.out.println("one");

case 2:

System.out.println("two");

}

1) default

2) default, zero

3) error default clause not defined

4) no output displayed

14. Which correctly create a two dimensional array of integers?

(a)int a[][] = new int [10,10];

(b)int a[10][10] = new int [][];

(c) int a[][] = new int [10][10];

(d) int []a[] = new int [10][10];

15. We have the following code:

if (a >4)

System.out.println("test1");

else if (a >9)

System.out.println("test2");

else

System.out.println("test3");

What will print 'test 2'?

A. less than 0

B. less than 4

C. between 4 and 9

D. greater than 9

E.None of the above

16. Which one does not extend https://www.360docs.net/doc/075263528.html,ng.Number

a)Integer

b)Boolean

c)Character

d)Long

e)Short

17. Public class Cycle

{ public static void main(String args[]){

System.out.println(args[0]);

}

}

if we compile our program by java Cycle one two, what will be output?

a) cycle

b) one

c) two

d)none

18. Which of the following are NOT Java modifiers?

a) public

b) private

c) friend

d) transient

19. What is the result of executing the following code when the value of x is 2:

switch (x)

{

case 1:

System.out.println(1);

case 2:

case 3:

System.out.println(3);

case 4:

System.out.println(4);

}

Select the most appropriate answer.

(a) Nothing is printed out

(b) The value 3 is printed out

(c) The values 3 and 4 are printed out

(d) The values 1, 3 and 4 are printed out

20. What does the zeroth element of the string array passed to the public static void main method contain?

Select the most appropriate answer

(a) The name of the program

(b) The number of arguments

(c) The first argument if one is present

(d) none of the above

21. What will be the result of compiling the following code:

public class Test

{

static int age;

public static void main (String args [])

{

age = age + 1;

System.out.println("The age is " + age);

}

}

Select the most appropriate answer.

(a) Compiles and runs with no output

(b) Compiles and runs printing out The age is 1

(c) Compiles but generates a runtime error

(d) Does not compile

(e) Compiles but generates a compile time error

22. Which of the following return true?

Select all correct answers.

(a) "john" == "john"

(b) "john".equals("john")

(c) "john" = "john"

(d) "john".equals(new Button("john"))

(e) none of the above

23. What is the result of executing the following code, using the parameters 4 and 0:

public void divide(int a, int b)

{

try

{

int c = a / b;

} catch (Exception e)

{

System.out.print("Exception ");

} finally

{

System.out.println("Finally");

}

}

Select the most appropriate answer.

(a) Prints out: Exception Finally

(b) Prints out: Finally

(c) Prints out: Exception

(d) No output

24. Which Exception will be generated if the array size is mentioned as negative?

(a) ArrayIndexOutOfBoundsException

(b) NegativeArraySizeException

(c) NumberFormatException

(d) IOException

25. Which of the following methods are defined on the Graphics class:

Select all correct answers.

(a) drawLine(int, int, int, int)

(b) drawImage(Image, int, int, ImageObserver)

(c) setVisible(boolean);

(d) none of the above

26. Given the following code what is the effect of ‘a’ being 5:

public class Test

{

public void add(int a)

{

for (int i = 1; i < 3; i++)

{

for (int j = 1; j < 3; j++)

{

if (a == 5)

{

break;

}

System.out.println(i * j);

}

}

}

}

Select the most appropriate answer.

(a) Generate a runtime error

(b) Throw an out of bounds exception

(c) Print the values: 1, 2, 2, 4

(d) Produces no output

27. What is the result of executing the following fragment of code:

boolean flag = true;

if (flag = true)

{

System.out.println("true");

}

else

{

System.out.println("false");

}

Select the most appropriate answer.

(a) true is printed to standard out

(b) false is printed to standard out

(c) An exception is raised

(d) Nothing happens

28. What happens when the following program is compiled and executed with the arguments java test. Select the one correct answer.

class test

{

public static void main(String args[])

{

if(args.length > 0)

System.out.println(args.length);

}

}

(a) The program compiles and runs but does not print anything.

(b) The program compiles and runs and prints 0

(c) The program compiles and runs and prints 1

(d) The program compiles and runs and prints 2

(e) The program does not compile.

29.What will be the output of the program

int j = 1;

while(j<5)

{

if(j == 1)

continue;

j++;

}

a) 1 b) 2, 3, 4 c) infinite loop d) 2, 3, 4, 5

30. The ______is a quantity whose value does changes during program execution

a) Variable b) constant c) expression d) none

31. What is the output of the following fragment.

int a = 11, b = 3, c;

c = a % b;

System.out.println( c );

a) 3 b) 2 c) 4 d) none

32.What is the output of the following fragment.

int a = 2 * (5 – 1) / (2 +1 );

System.out.print( a );

a) 2 b) 1 c) 3 d) none

33.What is the output of the following fragment.

int a = 2;

System.out.println( a++);

System.out.println( a);

System.out.println(++a);

a) 3, 3, 3 b) 3, 3, 4 c) 2, 3, 4 d) 2, 3, 3

34.________ are the Java programs that can be embedded in HTML.

a) Applets b) Applications c) JDK d) none

35.________ is responsible for building Graphical User Interface

a) JApplet b) AWT c) JOptionPane d) none

36. ------------- is nested in a class definition within another class and treated

like any other method of that class.

(a) inner class (b) static class (c)final class (d) none of the above

37. ----------- Returns a new string object containing the original

string of characters followed by the characters in the argument..

(a) concat() (b) charAt() (c) endsWith( ) (d) none of the above

38. -------------- is the process of deriving a class from a super

class or a base class.

(a) Polymorphism (b) Inheritance (c) encapsulation( ) (d) none

39. The attributes and methods declared as ------------ in the base

class can be accessed within the class and any of its derived class.

(a) public (b) private (c) protected( ) (d) none of the above

40. -------------- is the creation of a method in the subclass that has the same

signature, i.e., name, number and type of arguments, as a method in the

super

class.

(a) overloading (b) overriding (c) inheritance ( ) (d) none

41. The class can be declared as ------------, if instances or subclasses are not to be

created.

(a) final (b) static (c) abstract ( ) (d) none of the above

42.-------------- is an abnormal condition, which occurs during the execution of

a program.

(a) error (b) static (c) exception (d) none of the above

43.----------- block provides code that always executes, regardless of whether an

exception occurs or not.

(a) try (b) catch (c) finally (d) none of the above

44. ----------- exception is generated On entering characters as input.

(a)NumberFormatException (b) ArrayIndexOutOfBoundsException

(c) IOException (d) none of the above

45. -------- contain a set of classes in order to ensure that class names are unique.

(a)Packages (b) programs (c) subclasses (d) none of the above

46. ---------- tag is used to pass parameters in an applet.

(a)Parameters (b) PARAM (c) VALUE (d) none of the above

47. Initialization of all variables, creation of objects, setting of parameters, etc.

can be done in the ---------- method.

(a)Init (b) start (c) stop (d) none of the above

48. --------------- method loads an image from an URL which specifies the

location from which the image is to be loaded.

(a)loadImage (b) getImage (c) drawImage (d) none of the above

49. In a ------------- system, only one part of the program is in the process of

execution at any one time.

(a) single - threaded (b) multi-threaded (c) double-threaded (d) none

50. A ----------- is an object that implements a specific EventListener interface

extended from the generic java.util.EventListener.

(a) thread (b) event (c) Listener (d) none of the above

51. ----------- keyword is used, If we need to access the methods or variables in the

parent class whose method name is same to that of the derived class.

(a) super (b) this (c) static (d) none of the above

52. A ------------ is a method that is called when an object is created.

(a)this (b) constructor (c) start (d) none of the above

53. The -------- is used to find out the class name to which the object belongs.

(a)getObject (b) class (c) getClass (d) none of the above

54. The ------- keyword can be used where a reference to an object of the current

class type is required.

(a)super (b) this (c) new (d) none of the above

55. ------------- keyword is used to declare a class variable.

(a)super (b) this (c) static (d) none of the above

56. The ------- operator creates a single instance of a named class and return a

reference to that object.

(a)super (b) this (c) new (d) none of the above

57 The process of locating a particular element value in an array is called -----------.

(a)arranging (b) sorting (c) searching (d) none of the above

58---------------sort is to successively compare adjacent elements and swap them if they are out of order.

(a)bubble (b) random (c) linear (d) none of the above

59. ---------- can be defined as a collection of variables of same type that are

referred to by common name.

(a)collection (b) array (c) set (d) none of the above

60. The --------- statement, when executed in a while, for, do-while or switch

structure caused immediate exit from the structure.

(a)break (b) continue (c) loop (d) none of the above

61. In ---------- loop, the condition is checked at the last.

(a)while (b) do-while (c) loop (d) none of the above

62. ---------- method is used for finding the exponentiation of a number.

(a)pow (b) exp (c) power (d) none of the above

63. ----------- symbol is used to assign the value which is in the right hand side to the

variable which is in the left hand side.

(a)= (b) == (c) <> (d) none of the above

64. ------------- is the default browser which supports Java 2.

(a)internet explorer (b) netscape navigator (c) oprah (d) none

65. ------------- relational operator is used for representing "not equal to" condition.

(a)` (b) != (c) <> (d) none of the above

66. ________ method is used to obtain the path of .class file

(a) getCodeBase( ) (b) getClass( ) (c) getDocumentBase( ) (d) none

67. The -------- statement, when executed in a while, for or do-while structure, skips

the remaining statements in the loop body and proceeds with the next iteration of the loop.

(a)break (b) continue (c)loop (d) none of the above

68.An array index starts with -----

(a)0 (b) 1 (c)-1 (d) none of the above

69. The -------- methods and variables cannot be seen by any class other than the one in which they are defined.

(a)protected (b)public (c)private (d) none of the above

70.------------- is used to accept input from the user.

(a)stream (b)InputStreamReader (c)outputstreamreader (d) none

PART B (2 * 10 = 20 Marks)

(Note: Write any 2 programs from the following questions.)

1.Write a program to sort the given array in Ascending order

2.Write a program to draw the given shapes in the Applet

a)Line

b)Rectangle

c)Polygon

d)Arc

e)Oval

3.Write an error handling program to divide two numbers when divided

by zero

PART C (1 * 10 = 10 Marks)

(Note: Find out the errors in the following program and write down the correct program.)

1.

import javax . awt . *;

public class nonstaticmethod

{

String x, y;

static int z;

void getdata()

{

int a, b;

a = JOptionPane.showInputDialog("Enter the first

no");

b = JOptionPane.showInputDialog("Enter the second no");

x = Integer.parseInt(a);

y = Integer.parseInt(b);

}

void display()

{

system.out.println(" The result of x + y is " + (x+y));

}

Public Static Void Main(string args[])

{

nonstaticmethod obj1 = new nonstaticmethod();

getdata();

display();

z = 10000;

System.out.println("The value of class variable z is " + z );

}

}

华东交通大学2003—2004学年第二学期考试卷 Java语言课程课程类别：必、限、任