武科大java实验答案全.docx

1、武科大java实验答案全补充第一节的内容public class MyJavaClass int a; myjavaclass(int a)this.a=a; public void main() myjavaclass c1=new MyJavaClass();System.out.printIn(c1.a);System.out.printIn(程序结束。);1.上面的程序有几处错误？请依次改正。2.这个程序的源代码应该保存为什么名字的文件？ 3.请写出编译和运行这个文件的完整命令，注意给出环境变量的设置（假设源文件保存在d:java目录）4.如果在程序最前面加入下面语句：package

2、Pkg;该程序又该如何编译和运行？答案：答案（1）：修改以后的程序为（粗体为修改过的地方）public class MyJavaClass int a; MyJavaClass(int a)this.a=a; public Static void main(String args) MyJavaClass c1=new MyJavaClass(2) /此处的实际参数可为任意整数; System.out.println(c1.a); System.out.println(程序结束。); 答案（2） public class MyJavaClass int a; int myjavaClass(i

3、nt a)this.a=a;return a;/注此处函数返回值可为任意类型 public static void main(String args) MyJavaClass c1=new MyJavaClass(); System.out.println(c1.a)；System.out.println(程序结束。); 2、答案：这个程序的源代码应该保存为MyJavaClass.java。 3、答案(1)set class=c:j2sdkbin set classpath=d:java 编译：javac d:javaMyJavaClass.java 运行：java MyJavaClass 答

4、案（2）编译：c:j2sdkbinjavac d:javaMyJavaClass.java set classpath=d:java 运行：java MyJavaClass 4、答案：如果在程序最前面加入语句：package pkg;环境变量同3、设置编译：javac -d . d:javaMyJavaClass.java 运行：java pkg.MyJavaClass I 实验1答案1-(1-1)：import java.io.*;class RandomMonthpublic static void main(String args) String months=January,Febru

5、ary,March, April,May,June,July, Aguest,September,October, November,December; int i; i = (int)(Math.random() * 12); System.out.println(monthsi); 1-(1-2)：import java.io.*;import java.util.*;class RandomMonth2 public static void main(String args) String months=January,February,March, April,May,June,Jul

6、y, Aguest,September,October, November,December; Random r=new Random(); int i; i = Math.abs(r.nextInt()%12; System.out.println(monthsi); 1-(2)import java.util.*;class RandomPx public static void main(String args) int num=new int20; int i,j,temp; Random r=new Random(); for(i=0;i20;i+) numi=r.nextInt()

7、; for(i=0;i19;i+) for(j=0;jnumj+1) temp=numj; numj=numj+1; numj+1=temp; for(i=0;i=School.getscoreLine()| (s.getscore()96 & s.getcomScore()=300) ) return true; else return false; public static void main(String args) Student s=new Student3; String info=new String4; int i,j; String messInfo; BufferedRe

8、ader in=new BufferedReader(new InputStreamReader(System.in); StringTokenizer st; School.setscoreLine(550); for( i=0;is.length;i+ ) try messInfo=in.readLine(); st=new StringTokenizer(messInfo); for(j=0;jinfo.length;j+) infoj=st.nextToken(); catch(IOException ex) si=new Student(info0,info1,Float.parse

9、Float(info2),Float.parseFloat(info3); for(i=0;is.length;i+) if(isEnroll(si) System.out.println(si.name+ +si.id + + 被录取!); else System.out.println(si.name+ +si.id + + 没有录取!); 2-(3)思考题：import java.io.*;class Complex double RealPart; double ImageinPart; Complex(double rp,double ip) RealPart=rp; Imagein

10、Part=ip; Complex complexAdd(Complex a) Complex temp; temp=new Complex(RealPart+a.RealPart,ImageinPart+a.ImageinPart); return temp; Complex complexMinus(Complex a) Complex temp; temp=new Complex(RealPart-a.RealPart,ImageinPart-a.ImageinPart); return temp; public String toString() if (ImageinPart0) re

11、turn (RealPart+-+Math.abs(ImageinPart)+i); else return (RealPart+ImageinPart*+i); class ComplexApp public static void main(String args) char operator; try Complex c1=new Complex(1,2); Complex c2=new Complex(3,4); Complex complexResult; operator=(char)System.in.read(); switch(operator) case +:complex

12、Result=plexAdd(c2);break; case -:complexResult=plexMinus(c2);break; System.out.println(complexResult); catch(IOException e) System.out.println(e); III实验3 答案3-(1)1、class Person public String name; public String sex; int age; Person(String name,String sex,int age) this.name=name; this.sex=sex; this.ag

13、e=age; class Student extends Person public String sno; public int classno; public void updateAge(int age) this.age=age; Student(String name,String sex,int age,String sno,int classno) super(name,sex,age); this.sno=sno; this.classno=classno; public String toString() System.out.println(name=+name+ sex=

14、+sex + age=+age+ sno=+sno+ classno+classno+ ); return name=+name+ sex=+sex + age=+age+ sno=+sno+ classno+classno+ ; ;public class TestStudent public static void main(String args) Student s1=new Student(susan,女,20,20031015123,2); s1.updateAge(21); s1.toString(); 3-(3)import java.util.*;abstract class

15、 Employee String name; long no; static long id=1000; abstract double getPay(); Employee(String name) this.name=name;id=id+1; ;class Manager extends Employee double pay=8000; double getPay()return 8000; Manager(String name) super(name); no=id; public String toString()return name:+name+ no:+no+ pay:80

16、00;class Sale extends Employee long saleNum; double getPay()return saleNum*0.4; Sale(String name,long saleNum) super(name); no=id; this.saleNum=saleNum; public String toString() return name:+name+ no:+no+ pay:+getPay();class Tech extends Employee long salaryHours; double getPay() return salaryHours*

17、100; Tech(String name,long salaryHours) super(name); no=id; this.salaryHours=salaryHours; public String toString() return name:+name+ no:+no+ pay:+getPay();class EmployApp public static void main(String args) Vector v=new Vector(); Employee em; double numPay=0; v.addElement(new Sale(liping,10000); v

18、.addElement(new Sale(susan,12000); v.addElement(new Tech(linda,40); v.addElement(new Tech(write,20); v.addElement(new Manager(gucci); v.addElement(new Manager(jessica); Enumeration e=v.elements(); while(e.hasMoreElements() em=(Employee)e.nextElement(); numPay=numPay+em.getPay(); System.out.println(e

19、m); System.out.println(总工资:+numPay); ;实验4 答案4-(1)import java.lang.*;import java.io.*;class TestException public static void main(String args) try outofBound(); arraySize(); nullPointer(); catch(NegativeArraySizeException e) System.out.println(e.toString(); static void outofBound() try int i;int a; a

20、=new int10; for(i=0;i11;i+) ai=i; System.out.println(a+i+=+ ai); catch(IndexOutOfBoundsException e) System.out.println(e.toString(); static void nullPointer() try String s=null; System.out.println(s.length(); catch(NullPointerException e) System.out.println(e.toString(); static void arraySize() thro

21、ws NegativeArraySizeException try int a; a=new int-3; catch(NegativeArraySizeException e) throw e; 4-(2)class MyException extends Exception private String Msg; public MyException(String message) super(message); Msg=message; public void printMsg() System.out.println(Msg); public class EX6_3 void Gene

22、rateMyException() throws MyException throw new MyException(此处发生异常信息); public static void main(String args) EX6_3 obj=new EX6_3(); try obj.GenerateMyException(); catch (MyException e) e.printMsg(); 4-(3)思考题class NullParameterException extends Exception NullParameterException(String Message) super(Mes

23、sage); ;class TestArea public static void main(String args) shape sh=null; int num; num=args.length; try switch(num) case 1:sh=new Zangle(Double.parseDouble(args0); break; Case 2:sh=new Longangle(Double.parseDouble(args0),Double.parseDouble(args1);break; case 3:sh=new Triangle(Double.parseDouble(args0),Double.parseDouble(args1),Double.parseDouble(args2);break; case 0:throw new NullParameterException(参数个数为零！); System.out.println(sh.area(); catch(Exception e) System.out.println(e.toString(); ;abstract class shape abstract double area();class Triangle ext