Java东华理工大学试卷C.doc

专业 班级 学号 姓名 温馨提示：端正考风、严肃考纪、诚信参加考试 凡是代考、使用通讯设备作弊、二次作弊，一经发现开除学籍。东华理工大学2012 2013 学年第 1 学期考试试卷 JAVA程序设计 课程 闭卷 课程类别：考查 补考题号一二三四五六七八九总分分数评卷人1 选择题（共35分）1.Choose the invalid identifiers from those listed below. （ ） A. IDoLikeTheLongNameClass B. $byte C. true D. _ok 2. How can you force garbage collection of an object? （ ）A. Garbage collection cannot be forced B. Call System.gc(). C. Call System.gc(), passing in a reference to the object to be garbage collected. D. Call Runtime.gc(). E. Set all references to the object to new values（null, for example）. 3 Consider the following class: 1. class Test(int i) 2. void test(int i) 3. System.out.println(“I am an int.”); 4. 5. void test(String s) 6. System.out.println(“I am a string.”); 7. 8. 9. public static void main(String args) 10. Test t=new Test(); 11. char ch=“y”; 12. t.test(ch); 13. 14. Which of the statements below is true?( .) A. Line 5 will not compile, because void methods cannot be overridden. B. Line 12 will not compile, because there is no version of test() that rakes a char argument. C. The code will compile but will throw an exception at line 12. D. The code will compile and produce the following output: I am an int. 4. Which of the following lines of code will compile without error？ （ ） A. int i=0; if (i) System.out.println(“Hi”); B. boolean b=0; boolean b2=true; if(b=b2) System.out.println(“So true”); C. int i=1; int j=2; if(i=1| j=2) System.out.println(“OK”); D. int i=1; int j=2; if (i=1 &| j=2) System.out.println(“OK”); 5. Which two demonstrate a has a relationship? ( ) A. public interface Person public class Employee extends Person B. public interface Shape public interface Rectandle extends Shape C. public interface Colorable public class Shape implements Colorable D. public class Species public class Animalprivate Species species; 6 True or False: Readers have methods that can read and return floats and doubles. （ ） A. Ture B. False C no answer7 What is result ( ) class Test public static void main(String args) int a=2; System.out.println(a+);A 2 B 3 C 1 D 48 What is result ( ) class Test public static void main(String args) int a=2,b=3; System.out.println(a+b+);A 2 B 3 C 5 D 49 which platform is not belonging to Java developing platform ( )A j2ee B j2me C j2se D jsp10 what expression is incorrect( )A .class file is byte codeB .class file is based on JVMC .class file is run by real CPUD .class file is produced by javac11 what statement is valid ( )A extend is used as implementing hierarchy between both classesB extends is used as implementing hierarchy between both interfaceC implement is used between interface and classD implements is used as implementing hierarchy between both interface12 Which statement is invalid ( )A int a5; B int a =1,2,4 C int a=new int313 Which sentence is right( ) A abstract final class A B abstract private class A C abstract protected class A D abstract class A14 How to compile a Java source code ( ) A javac a.java B java a.java C javac a D javac a.class 15 Set x=1,y=2,z=3, expression y-=z-%+x; what is result ( ) A 1 B 3.5 C 4 D 5二 翻译题20分，每小题5分1）Inheritance is a relatively simple concept, which allows one class to extend another, or to inherit characteristics. When a class is extended a hierarchy is built up with the original class at the top and the classes, which build on the class above it (the class at the top is known as the super-class below). When a class is extended, to create a sub-class, all of the properties (variables and methods) of the original class still exist within the new class along with others, which have been added.2）Polymorphism is the ability of objects to react differently when presented with different information, known as parameters. In a functional programming language the only way to complete two different tasks is to have two functions with different names. Object-oriented languages, which include Java, allow different methods to be run depending on what type of parameters is specified. 3）A Java application resembles programs in most compiled languages. Code in object format resides on the users machine and is executed by a run-time interpreter that normally has to be user installed.4）Keywords cannot be used for anything but their predefined purpose. There are 49 in all, These words each have a special meaning to the Java compiler. A keyword must be separated from other keywords or identifiers by white space, a comment or some other punctation symbol.三 程序阅读题(每题4分，共计20分)：The result of following program is:_public class Class1public static void main(String args)int n=6,sum=0;for(int k=1;k=n;k+)if (n%k=0)sum+=k;System.out.println(sum);The result of following program is: _public class Person String name;int age;public Person(String name, int age) = name;this.age = age;public static void main(String args) Person c = new Person(Peter, 17);System.out.println( + is + c.age + years old!);The result of following program is: _public class OverLoadingOrderstatic void print(String s,int i)System.out.println(String: +s+ ,int: +i);static void print(int i,String s)System.out.println(int: +i+, String: +s);public static void main(String arg)print(String first,11);print(99,Int first);The result of following program is: _class MammalClassString name,eyeColor;int age;public MammalClass()name=TheName;eyeColor=Black;age=0;class DogClass extends MammalClassboolean hasTail;public DogClass()name=Chase;eyeColor=Black;age=2;hasTail=true;class ManClass extends MammalClassboolean isMarried;public ManClass()name=Casey;eyeColor=Blue;age=1;isMarried=true;public class L05_07_inheritanceDemopublic static void main(String args)DogClass dog1=new DogClass();ManClass