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. publicB. staticC.protectedD.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. 0B. 1C. 2D. 35、Java中，（）类是所有类的最终祖先？A. StringB. NuberC. LangD. Object6、以下标识符中哪项是不合法的( )A. GreatB. manyC. intD. _x17、 Java语言中，长整数占用的存储字节数是( )。

A. 4B. 8C. 16D.28、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.appletB. java.awtC. ngD. java.util11、通过哪个方法可以改变按钮的颜色A． setColor B. setBackgroundC. getBackground E. setForeground12、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JavacB. Javac和JavaC. Javap和JavaD. Javac和Jdb13、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. 0B. 1C. 2D. 314. 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）0x816. 给出以下程序段：boolean m = true;if ( m )System.out.println("False");elseSystem.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test19. 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 12. 要改变一个字符串的内容可以使用StringBuffer类 13．多线程程序必须编写run()方法。

14．Socket通信中服务方要创建Socket对象并监听客户连接。

15．Java程序中可使用throws语句明确抛出例外对象。

16．Vector对象中可以存储不同类型的对象。

17．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){=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="++",age="+x1.age); System.out.println("name="++",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 codec) Hexadecimal code d) None of the above.2. 2. The ______ is the mechanism that binds the data and functions togetherwith eachother and keeps both safe from outside interference.a) Encapsulation b) Polymorphism c) Inheritance d) None3. 3. Java programs should be saved with the extensiona) .c b) .txt c) .java d) .doc4. 4. ______ do not cause the computer to perform any action when theprogram is run.a) Comments b) the keyword Class c) Main method d) None5. 5. When ________ appears in a string of characters, Java combines thenextcharacter and forms the escape sequence.a) front slash ( / ) b) back slash ( \ ) c) commentsd) None6. 6. Java’s numerous predefined classes are grouped into categories orrelated classescalled ______a) Objects b) Classes c) Library d) Packages7.7. The name of the package with “java” is calleda) Core packages b) Extension package c) Both a & bd) None8.8. The _______ class provides prepackaged dialog boxes that enables usto displayboxes.a) JApplet b) Graphics c) Container d) JoptionPane9.9. The ________ statement is used to include all the necessary classesinto ourprogram from the specified package.a) class definition b) import c) main definition d) None1 10 ._______ is the method which is used to read the value from the userwhich comesunder the class JoptionPane.a) showMessageDialog( ) b) showInputDialog( )c) System.out d) System.in1 11.The method which is used to convert the String value to Integer valuea) parseDouble b) parseInt c)parseFloat d)none12. What will be printed out if you attempt to compile and run the followingcode ?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) one2) one, default3) one, two, default4) default13. 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) default2) default, zero3) error default clause not defined4) no output displayed14. 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");elseSystem.out.println("test3");What will print 'test 2'?A. less than 0B. less than 4C. between 4 and 9D. greater than 9E.None of the above16. Which one does not extend ng.Numbera)Integerb)Booleanc)Characterd)Longe)Short17. 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) cycleb) onec) twod)none18. Which of the following are NOT Java modifiers?a) publicb) privatec) friendd) transient19. 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 out20. 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 above21. 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 error22. 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 above23. 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 output24. Which Exception will be generated if the array size is mentioned as negative?(a) ArrayIndexOutOfBoundsException(b) NegativeArraySizeException(c) NumberFormatException(d) IOException25. 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 above26. 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 output27. 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 happens28. 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 programint j = 1;while(j<5){if(j == 1)continue;j++;}a) 1 b) 2, 3, 4 c) infinite loop d) 2, 3, 4, 530. The ______is a quantity whose value does changes during program executiona) Variable b) constant c) expression d) none31. 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) none32.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) none33.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, 334.________ are the Java programs that can be embedded in HTML.a) Applets b) Applications c) JDK d) none35.________ is responsible for building Graphical User Interfacea) JApplet b) AWT c) JOptionPane d) none36. ------------- is nested in a class definition within another class and treatedlike any other method of that class.(a) inner class (b) static class (c)final class (d) none of the above37. ----------- Returns a new string object containing the originalstring of characters followed by the characters in the argument..(a) concat() (b) charAt() (c) endsWith( ) (d) none of the above38. -------------- is the process of deriving a class from a superclass or a base class.(a) Polymorphism (b) Inheritance (c) encapsulation( ) (d) none39. The attributes and methods declared as ------------ in the baseclass can be accessed within the class and any of its derived class.(a) public (b) private (c) protected( ) (d) none of the above40. -------------- is the creation of a method in the subclass that has the samesignature, i.e., name, number and type of arguments, as a method in thesuperclass.(a) overloading (b) overriding (c) inheritance ( ) (d) none41. The class can be declared as ------------, if instances or subclasses are not to becreated.(a) final (b) static (c) abstract ( ) (d) none of the above42.-------------- is an abnormal condition, which occurs during the execution ofa program.(a) error (b) static (c) exception (d) none of the above43.----------- block provides code that always executes, regardless of whether anexception occurs or not.(a) try (b) catch (c) finally (d) none of the above44. ----------- exception is generated On entering characters as input.(a)NumberFormatException (b) ArrayIndexOutOfBoundsException(c) IOException (d) none of the above45. -------- contain a set of classes in order to ensure that class names are unique.(a)Packages (b) programs (c) subclasses (d) none of the above46. ---------- tag is used to pass parameters in an applet.(a)Parameters (b) PARAM (c) VALUE (d) none of the above47. 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 above48. --------------- method loads an image from an URL which specifies thelocation from which the image is to be loaded.(a)loadImage (b) getImage (c) drawImage (d) none of the above49. In a ------------- system, only one part of the program is in the process ofexecution at any one time.(a) single - threaded (b) multi-threaded (c) double-threaded (d) none50. A ----------- is an object that implements a specific EventListener interfaceextended from the generic java.util.EventListener.(a) thread (b) event (c) Listener (d) none of the above51. ----------- keyword is used, If we need to access the methods or variables in theparent class whose method name is same to that of the derived class.(a) super (b) this (c) static (d) none of the above52. A ------------ is a method that is called when an object is created.(a)this (b) constructor (c) start (d) none of the above53. The -------- is used to find out the class name to which the object belongs.(a)getObject (b) class (c) getClass (d) none of the above54. The ------- keyword can be used where a reference to an object of the currentclass type is required.(a)super (b) this (c) new (d) none of the above55. ------------- keyword is used to declare a class variable.(a)super (b) this (c) static (d) none of the above56. The ------- operator creates a single instance of a named class and return areference to that object.(a)super (b) this (c) new (d) none of the above57 The process of locating a particular element value in an array is called -----------.(a)arranging (b) sorting (c) searching (d) none of the above58---------------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 above59. ---------- can be defined as a collection of variables of same type that arereferred to by common name.(a)collection (b) array (c) set (d) none of the above60. The --------- statement, when executed in a while, for, do-while or switchstructure caused immediate exit from the structure.(a)break (b) continue (c) loop (d) none of the above61. In ---------- loop, the condition is checked at the last.(a)while (b) do-while (c) loop (d) none of the above62. ---------- method is used for finding the exponentiation of a number.(a)pow (b) exp (c) power (d) none of the above63. ----------- symbol is used to assign the value which is in the right hand side to thevariable which is in the left hand side.(a)= (b) == (c) <> (d) none of the above64. ------------- is the default browser which supports Java 2.(a)internet explorer (b) netscape navigator (c) oprah (d) none65. ------------- relational operator is used for representing "not equal to" condition.(a)` (b) != (c) <> (d) none of the above66. ________ method is used to obtain the path of .class file(a) getCodeBase( ) (b) getClass( ) (c) getDocumentBase( ) (d) none67. The -------- statement, when executed in a while, for or do-while structure, skipsthe 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 above68.An array index starts with -----(a)0 (b) 1 (c)-1 (d) none of the above69. 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 above70.------------- is used to accept input from the user.(a)stream (b)InputStreamReader (c)outputstreamreader (d) nonePART 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 order2.Write a program to draw the given shapes in the Appleta)Lineb)Rectanglec)Polygond)Arce)Oval3.Write an error handling program to divide two numbers when dividedby zeroPART 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 firstno");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、任闭卷（）、开卷(范围)（）：一、选择題（40分）1、设有如下定义：String s = " Example ";以下哪些语句合法？A. s >>>= 3;B. s[3] = "x";C. int i = s.length();D. String t = "For " + s;E. String shortS = s.trim();2、设有以下代码public class Test {String animals = null;public static void main(String []args) {<<statement>>}}执行时输入：java Test cat horse在<<statement>>处如何能将'cat' 赋值给animals 变量?A. animals = args(0);B. String animals = args(0);C. animals =args(1);D. String animals = args(1);3、以下哪些标识符是合法的A. $FredB. thisC. _thisD.instanceE.2for4、以下代码：if (a >4)System.out.println("test1");else if (a >9)System.out.println("test2");elseSystem.out.println("test3");A为何值将有输出结果test 2 ？A. 小于 0B. 小于 4C. 4 和9之间D. 大于9E.无任何可能5、指出正确的表达式A． double a=1.0;B． Double a=new Double(1.0);C． byte a = 340;D． Byte a = 120;6、当参数为4和0时，以下程序的执行结果为：public void divide(int a, int b) {try {int c = a / b;} catch (Exception e) {System.out.print("Exception ");} finally {System.out.println("Finally");}}A) 输出 Exception FinallyB) 输出 FinallyC) 输出 ExceptionD) 无输出7、在Java中，开发图形用户界面的程序需要使用一个系统提供的类库，这个类库就是（）包。