序言

先說在前面，如果本電子版侵犯了原書的版權(quán)，請立即刪除。本電子版用于個人學習交流，嚴禁用于

商業(yè)出版。

本電子版答案的java源代碼源自于《Java程序設(shè)計（第二版）題解與上機指導(dǎo)》，本人對該書的全部源代

碼都進行了編輯，編譯，運行等工作，修改了其中的錯誤源代碼。不過有些題目的解答實在是莫米其妙本

人也無法理解原作者的意思，本人會在最后給出其他例子用來彌補此之不足。其中加入了大量的注釋說明

語句，這些是原書所沒有的。這些代碼在jbuilder9.0卜.調(diào)試通過，部分的是在jbuilder2006卜調(diào)試通過

的，還有在jcreator下調(diào)試通過的。其中大部分源代碼在jbuilder9.0下就能編譯運行。還有一些源代碼

是需要更高的jdk版本才能編譯運行，所以這些源代碼就在jbuilder2006卜.編譯運行。Jbuilder9.0自帶

的jdk是jdkl.4的，jbuilder2006自帶的jdk是jdkl.5的。特別說明的是jbuilder2006所支持的字體

特別少，要想加入宋體等其他字體的方法請參看839682048的空間。

ed2k:〃Ifilel%5BJBuiIder.2006.%E4%BC%81%E4%B8%9A%E5%AE%8C%E6%95%B4%E7%89%88%5D.JB2006CD1%5B

free_guru%5D.rar（68782371043a2e30e546edf87edcbe426fb9fe600|h=sbmjqn54tio7msl331vabc4jtuz41g

cnl/

以上是jbuilder2006Windo\vs平臺的下載地址，復(fù)制以上代碼，打開迅雷，新建，就可以下載了，里面有

破解補丁。安裝需要虛擬光驅(qū)。

眾所周知，程序設(shè)計題目的答案是不唯一的，讀者發(fā)揮的潛能很大。本電子版是為了方便讀者，使其免去

輸代碼這一關(guān)鍵步驟。因為原書的作者的水平有限，本人的水平也有限，難免有錯誤和不妥之處，實現(xiàn)的

代碼也不一定是最優(yōu)的，讀者可以參考本電子版答案和其他參考書的內(nèi)容，給出更全面的答案，懇請廣大

讀者特別是同行專家批評指正。

（通過閱讀原書，我發(fā)現(xiàn)作者編寫此書的態(tài)度不是很認真，不像此書同系列的譚浩強的《c程序設(shè)計》一

歸那樣認真嚴謹。不過還是要感謝原書作者。在此也懇請所有出書的人要抱著?種對讀者，特別是對中國

的讀者負責的認真態(tài)度。）

如果你有什么疑問可以和本人聯(lián)系839682048<>。

最后，在此祝愿所有讀者，特別是中國的讀者：學業(yè)有成，事業(yè)更上一層樓。讓我們一起為中國的計算機

發(fā)展而努力奮斗吧?。?！

〃習題2.2

importjava.util.*;

classMyDate{

privateintyear;

privateintmonth;

privateintday;

publicMyDate(inty,intm,intd){〃構(gòu)造函數(shù),構(gòu)造方法

year=y;

month=m;

day=d;

}//endpublicMyDate(inty,intin,intd)

publicintgetYearO{〃返回年

returnyear;

)//endgetYear()

publicintgetMonth。{〃返回月

returnmonth;

}//endgetMonthO

publicintgetDay(){〃返回日

returnday;

}//endgetDay0

}//endclassMyDate

classEmployee{

privateStringname;

privatedoublesalary;

privateMyDatehireDay;

publicEmployee(Stringn,doubles,MyDated){

name=n;

salary二s;

hireDay=d;

}//endpublicEmployee(Stringn,doubles,MyDated)

publicvoidprint(){

System.out.printin(〃名字："+name+"\n工資："+salary+"\n雇傭年份:"+hireYear()+"\n");

}//endprint()

publicvoidraiseSalary(doublebyPercent){

salary*=l+byPercent/100;

}//end

publicinthireYearO{

returnhireDay.getYearO;

)

}//endclassEmployee

publicclassMyTestClass{

publicstaticvoidmain(String[]args){

Employee[]staff=newEmployee[3]：

staff[O]=newEmployee(?，HarryHacker^,35000,newMyDate(1989,10,1));

staff[l]=newEmployeeC'CarlCarcker*,75000,newMyDate(1987,12,15));

staff[2]=newEmployee(z，TonyTester*,38000,newMyDate(1990,3,12));

intintegerValue;

System,out.printin(''Theinformationofemployeeare:");

for(integerValue=0;integerValue<=2;integerValue++){

staff[integerValue].raiseSalary(5);

}//endfor()

for(integerValue=0;integerValue<=2;integerValue++){

staff[integerValue].print();

}//endfor0

}//endmain()

}//endclassMyTestClass

〃習題2.4

importjava,util.*;

publicclassDataType{

publicstaticvoidmain(String[]args){

booleanflag;

charyesChar;

bytefinByte;

intintValue;

longlongValue;

shortshortValue;

floatfloatValue;

doubledoubleValue;

flag=true;

yesChar='y，;

finByte=30;

intValue=-7000;

longValue=2001;

shortValue=20000;

floatValue=9.997E-5f;

doubleValue=floatValue*floatValue;

System,out.printin(z，thevaluesare:");

System.out.printin("布爾類型變量flag=，，+flag);

System,oul.printin("字符型變量yesChar=〃+yesChar);

System.out.printin(〃字節(jié)型變量finByte="+finByte);

System,out.prinlln("整型變量intValue=/z+intValue);

System.out.printin(“長整型變量longValue=z，+longValue);

System,oul.prinlln(〃短整型變量shortValue="z+shortValue);

System.out.printin(“浮點型變量floatValue=z，+floatValue);

System.out.printin(“雙精度浮點型變量doubleValue=z/+doubleValue);

}//endmain()

}

〃習題2.9

importjava,util.*;

classPubTestl{

privateintivarl;

privatefloatfvarl,fvar2;

publicPubTestl(){

fvar2=0.Of;

}

publicfloatsum_f_I(){

fvar2=fvarl+ivarl;

returnfvar2;

}

publicvoidprint(){

System,out.printin(/，fvar2="z+fvar2);

}

publicvoidsetlvarl(intivalue){

ivarl=ivalue;

)

publicvoidsetFvarl(floativalue){

fvarl=ivalue;

}

}

publicclassPubMainTest{

publicstaticvoidmain(String[]args){

PubTestlpubtl=newPubTestl();

pubt1.setlvarl(10);

pubtl.setFvarl(100.02f);

pubtl.sum_f_I();

pubtl.print0;

}

}

〃習題2.10

importjava,util.*;

classDate{

privateintyear;

privateintmonth;

privateintday;

publicDate(intday,intmonth,intyear){〃構(gòu)造函數(shù)，構(gòu)造方法

this.year=year;

this,month=month;

this,day=day;

}//endpublicMyDate(inty,intm,intd)

publicintgetYear(){〃返回年

returnyear;

}//endgetYear()

publicintgetMonthO{//返回月

returnmonth;

}//endgetMonthO

publicintgetDayO{〃返回日

returnday;

}//endgetDay()

)//endclassDate

publicclassTeacher{

Stringname;〃教師名字

booleansex;〃性別，true表示男性

Datebirth;〃出生日期

StringsalarylD;〃工資號

Stringdepart;〃教師所在系所

Stringposit;〃教師職稱

StringgetName(){

returnname;

)

voidsetName(Stringname){

this,name=name;

)

booleangetSex(){

returnsex;

)

voidsetSex(booleansex){

this.sex=sex;

)

DategetBirthO{

returnbirth;

)

voidsetBirth(Datebirth){

this,birth=birth;

)

StringgetSalaryID(){

returnsalaryID;

}

voidsetSalaryll)(StringsalaryID){

this.salarylD=salarylD;

StringgetDepart(){

returndepart;

)

voidsetDepart(Stringdepart)(

this.depart=depart;

}

StringgetPosit(){

returnposit;

}

voidsetPosit(Stringposit)(

this,posit=posit;

}

publicTeacher(){

System.out.printin("父類無參數(shù)的構(gòu)造方法!!!!!!!");

"/如果這里不加上這個無參數(shù)的構(gòu)造方法將會出錯?。。?！

publicTeacher(Stringname,booleansex,Datebirth,

Stringsalaryid,Stringdepart,Stringposit){

=name;

this,sex=sex;

this.birth=birth;

this.salaryID=salaryid;

this.depart=depart;

this,posil=posit;

}//endTeacher()

publicvoidprint(){

System,out.print("theteacher,name:");

System,out.println(this.getName());

System,out.print(z/theteacher*sex:〃)；

if(this.getSex()==false){

System,out.printin(〃女”)；

)

else{

System.out.printIn(，z5]^);

}

System.out.print("theteacher,birth:〃)；

System,out.printIn(this.getBirth().getYear()+“-"+

this.getBirthO.getMonth()+〃-"+

this.getBirthO.getDay());

System,out.print("theteacher'salaryid:〃)；

System,out.printin(this.getSalarylDO);

System.out.print("theteacher,posit:〃);

System,out.println(this.getPosit());

System,out.print("theteacher*depart:〃)；

System,out.print1n(this.getDepart());

}//endprint()

publicstaticvoidmain(StringE]args){

Datedll=newDate(11,23,1989);

Datedt2=newDate(2,6,1975);

Datedt3=newDate(11,8,1964);

Datedt4=newDate(10,4,1975);

Datedt5=newDate(8,9,1969);

〃創(chuàng)建各系教師實例，用來測試

Teachertl二newTeacher(“王瑩"，false,dll,“123","經(jīng)濟學"，"prefessor");

ResearchTeacherrt=newResearchTeacher("楊zi青"，true,dt2,〃421〃，"軟件工程”,

“associateprefessor*,“software");

LabTeacherlat=newLabTeacher("王夏理〃,false,dt3,"163”,〃外語〃,

“pinslrucor","speechlab");

LibTeacherlit=newLibTeacher(〃馬二孩"，true,dt4,"521〃，”大學物理〃，

“prefessor","physicalLib");

AdminTeacherat=newAdminTeachcr(“王xi〃，false,dt5,〃663",〃環(huán)境”，

preiessor,dean);

〃〃〃〃/分別調(diào)用各自的輸出方法，輸出相應(yīng)信息〃〃〃/〃〃〃〃〃〃〃〃〃〃/

System,out.println(z，");

tl.print();〃普通教師信息

System,out.printinC〃)；

rt.print0;//研究系列教師信息

System,out.printin(/z〃)；

lat.print()；〃普通教師信息

System,out.printing〃);

lit.print。；〃實驗系列教師信息

System,out.printing");

at.print();〃行政系列教師信息

System,out.printing〃);

}//endmain()

}//endpublicclassTeacher

classResearchTeacherextendsTeacher{

privateStringresField;

publicResearchTeacher(Stringname,booleansex,Datebirth,Stringsalaryid,

Stringdepart,Stringposit,StringresField){

this,name=name;

this.sex=sex;

this,birth=birth;

this.salarylD=salaryid;

this.depart=depart;

this.posit=posit;

this.resField=resField;

}//endpublicResearchTeacher(){}

StringgetResFieldO{

returnresField;

)

voidsetResField(StringresField){

this.resField=resField;

)

publicvoidprint(){

System,out.print(''researchteacherinfois:〃)；

System,out.print(/ztheteacher*name:/z);

System,out.printin(this.getName0);

System,out.print("theteacher,sex:〃);

if(this.getSexO==false){

System.out.prinlln(〃女〃)；

)

else{

System,out.printing男”)；

)

System,out.print("theteacher*birth:〃)；

System,out.println(this.getBirthO.getYearO+"-"+

this.getBirthO.getMonthO+〃-"+

this.getBirthO.getDay());

System,out.print(，ztheteacher'salaryid:^);

System,out.println(this.getSalarylDO);

System,out.print("theteacher'posit:〃);

System.out.printin(this.getPosit());

System,out.print("theteacher*depart:");

System,out.println(this.getDepart());

System,out.print("theteacher*resField:");

System,out.println(this.getResField());

}//endprint()

}//endclassResearchTeacher

classLabTeacherextendsTeacher(

privateStringlabName;

publicLabTeacher(Stringname,booleansex,Datebirth,

Stringsalaryid,Stringdepart,

Stringposit,StringlabName){

=name;

this,sex=sex;

this.birth=birth;

this.salarylD=salaryid;

this.depart=depart;

this,posit=posit;

this.labName=labName;

)//endpublicResearchTeacher0{}

StringgetLabName(){

returnlabName;

}

voidsetLabName(StringlabName){

this.labName=labName;

)

publicvoidprint(){

System,out.print(/zlabteacherinfois:");

System,out.print("theteacher*name:;

System,out.printin(this.getName());

System,out.print("theteacher*sex:〃)；

if(this.getSex()二二false){

System.out.printin(〃女”)；

)

else{

System,out.printin("男〃);

)

System,out.print("theteacher，birth:〃)；

System,out.println(this.getBirth().getYearO+"-"+

this.getBirth().getMonthO+〃+

this.getBirthO.getDay());

System,out.print("theteacher,salaryid:〃)；

System.out.println(this.getSalarylDO);

System,out.print("theteacher*posit:〃);

System,out.println(this.getPosit());

System,out.print("theteacher,depart:〃)；

System.out.println(this.getDepart());

System,out.print(/ztheteacher*labName:*);

System.out.println(this.labName);

}//endprint()

}//endclassLabTeacher

classLibTeacherextendsTeacher{

privateString1ibName;

publicLibTeacher(Stringname,booleansex,Datebirth,

Stringsalaryid,Stringdepart,

Stringposit,StringlibName){

=name;

this,sex=sex;

this,birth=birth;

this.salarylD=salaryid;

this.depart=depart;

this.posit=posit;

this.libName=libName;

}//endpublicResearchTeacher(){}

StringgetLibNameO{

returnlibName;

)

voidsetLibName(StringlibName){

this.libName=libName;

}

publicvoidprint(){

System,out.print(z，libteacherinfois:〃)；

System,out.printC'theteacher'name:");

System,out.printin(this.getName0);

System,out.print("theteacher*sex:〃)；

if(this.getSexO==false){

System,out.printin("女");

)

else{

System,out.printin(〃男”)：

}

System.out.print("theteacher'birth:〃);

System,out.printin(this.getBirth().getYearO+"-"+

this.getBirthO.getMonthO+-

this.getBirthO.getDay());

System,out.print("theteacher,salaryid:*);

System,out.printin(this.getSalaryID());

System,out.print("theteacher,posit/);

System,out.printin(this.getPosit());

System.out.print("theteacher*depart:;

System,out.print1n(this.getDepart());

System.out.print("theteacher,libName:");

System,out.printIn(this.1ibName);

}//endprint()

}//endclassLibTeacher

classAdminTeacherextendsTeacher{

privateStringmanagePos;

publicAdminTeacher(Stringname,booleansex,Datebirth,

Stringsalaryid,Stringdepart,

Stringposit,StringmanagePos){

=name;

this,sex=sex;

this.birth=birth;

this.salarylD=salaryid;

this,depart=depart;

this,posit=posit;

this.managePos=managePos;

}//endpublicResearchTeacher(){}

StringgetManagePos(){

returnmanagePos;

)

voidsetManagePos(StringmanagePos){

this.managePos=managePos;

}

publicvoidprint(){

System,out.print(^adminteacherinfois:*);

System,out.printC'theteacher,name/');

System,out.printin(this.getName0);

System,out.print(/?theteacher,sex:");

if(this.getSexO==false){

System.out.prinlln(〃女〃);

)

else{

System,out.printin("男〃);

)

System,out.print(z/theteacher*birth:");

System,out.printIn(this.getBirthO.getYearO+"-〃+

this.getBirthO.getMonthO+"-〃+

this.getBirthO.getDay());

System,out.print(z/theteacher,salaryid:;

System.out.println(this.getSalarylDO);

System,out.print(z，theteacher'posit:");

System.out.println(this.getPosit());

System,out.print(，ztheteacher*depart:");

System,out.printin(this.getDepart());

System,out.print("theteacher'managePos:");

System,out.printin(this.managePos);

}//endprint()

}//endclassAdminTeacher

習題2.11

publicclassCourse{

privateStringcourselD;

privateStringcourseName;

privateStringcourseType;

privateintclassHour;

privatefloatcredit;

publicCourse(StringcourselD,StringcourseName,StringcourseType,

intclassHour,floatcredit){

this.courseID=courseID;

this.courseName=courseName;

this.courseType=courseType;

this,classHour=classHour;

this.credit=credit;

}//endpublicCourseO{}

StringgetID(){

returncourselD;

}

voidsetID(Stringid){

this.courselD=id;

StringgetName(){

returncourseName;

voidsetName(Stringname){

this.courseName二name;

StringgetType(){

returncourseType;

voidsetType(Stringtype){

this.courseType=type;

)

intgetClassHour(){

returnclassHour;

}

voidsetClassHour(inthour){

this.classHour=hour;

floatgetCredit(){

returnclassHour;

}

voidsetCredit(floatcredit){

this.credit=credit;

)

publicvoidprint(){

System,out.printin(z，thebasicinfoofthiscourseasfollowed:z，);

System.out.printin(/zcourseID="z+this.getIDO);

System,out.printin(，，courseName=*+this.getName0);

System,out.printinC/courseType^^+this.getType());

System.out.printIn("classHour=〃+this.getClassIIourO);

System,out.prinlln("credit="+lhis.getCredit());

)

publicstaticvoidmain(Stringf]args){

Coursecs=newCourse("dl2","java程序設(shè)計(第二版)"，"cs〃，64,3.Of);

System,out.printin(*");

cs.print();

System.out.printIn("修改課程學分為4.Of");

cs.setCredit(4);

cs.print();

〃習題2.12

publicclassMyGraphic{

StringlineColor;

StringfillColor;

MyGraphic(String1c,Stringfc){

this.lineColor=lc;

this.fillColor=fc;

)

voidprint0(

System,out.printin(z，linecoloris/z+this.lineColor+

“\tfillcolorisz，+this.fillColor);

}

publicstaticvoidmain(String[]args){

floatrd二(float)4.5;

MyCirclemc=newMyCircle(rd,"black","white");

MyRectanglemr=newMyRectangle(4,6,"red","blue");

System,out.printin(''Circleinfo〃)；

me.print0;

System,out.printin(^circumferenceis〃+me.calCircumO);

System,out.printin(''squareis"+me.calSquareO);

System,out.printin(^rectangleinfo:");

mr.print0;

System,out.printin(/zcircumferenceis〃+mr.calCircumO);

System,out.printIn(''squareis"+mr.calSquareO);

}//endmain(){}

}//endpublicclassMyGraphic

classMyRectangleextendsMyGraphic(

floatrLong;

floatrWidth;

MyRectangle(floatrl,floatrw,String1c,Stringfc){

super(1c,fc);

this.rLong=rl;

this.rWidth=rw;

}//endMyRectangle(){)

floatcalCircumO{

return((float)((this.rLong+this.rWidth)*2));

}

floatcalSquareO{

return((float)(this.rLong*this.rWidth));

}

}//endclassMyRectangle

classMyCircleextendsMyGraphic(

floatradius;

MyCircle(floatrd,String1c,Stringfc){

super(1c,fc);

this,radius二rd;

}//endMyRectangle(){}

floatcalCircumO{

return(float)((this.radius*3.12*2));

}

floatcalSquareO{

return((float)(this.radius*this.radius*3.14));

)

}//endclassMyCircle

〃習題2.13

publicclassVehicle{

Stringbrand;

Stringcolor;

intprice;

intnumber;

publicVehicle(Stringb,Stringc){

this.brand=b;

this.color=c;

}

publicVehicle(Stringb,Stringc,intp,intn){

this(b,c);

this,price=p;

this.number=n;

}

voidprint(){

System,out.printin(^Xn〃);

System,out.println(，zthevehicleinfoasfollowed

System,out.printIn("brand=〃+this,brand+"\t");

System,out.printlnC，color=/Z+this,color+〃\t");

System,out.printIn("price=〃+this,price+"\t");

System,out.printin("number=〃+this.number+〃\t〃)；

}//endvoidprint()

publicstaticvoidmain(String[]args){

Vehiclecl=newVehicle("vehicle1","white");

Vehiclec2=newVehicle(〃vehicle2〃，“white”,300,1);

Carcr=newCar("carl","red”,300,4,400);

Trucklk2=newTruck("iruckl","black”,300,400);

cl.print0;

c2.print();

cr.print0;

tk2.print();

}//endmainO

}//endpublicclassVehicle

classCarextendsVehicle{

intspeed;

Car(Stringb,Stringc,intp,intn,ints){

super(b,c,p,n);

this.speed=s;

)

voidprint0(

super,print();

System,out.print("speed—+this.speed);

}

}//endclassCar

classTruckextendsVehicle(

intspeed;

intweight;

Truck(Stringb,Stringc,ints,intw){

super(b,c);

this,speed's;

this.weight=w;

}

voidprint0(

super,print();

System,out.print("speed="+this.speed);

System,out.print("weight=〃+lhis.weight);

)

}//endclassTruck

〃習題3.3

publicclassTest{

publicstaticvoidmain(String[]args){

intbl=l;

intb2=l;

System.out.printin(“bl="+bl);

System,out.printIn(*62=*+b2);

bl?=31;

b2?=31;

System.out.prinlln(〃bl=〃+bl);

System.out.printin(“b2=〃+b2);

bl?=31;

System,out.printin(z，bl=/z+bl);

bl?=1;

System,out.printin("bl=〃+bl);

b2?>=31;

System,out.printIn(*62=*+b2);

b2?>=1;

System,out.printin(，，b2=/z+b2);

)

〃習題3.4

publicclassFactorial{

privateintresult,initVal;

publicstaticintFactorial(intn){

if(n=0){

return1;

)

returnn*Factorial(n-1);

}

publicvoidprint(){

System,out.println(initVal+/，!=/z+result);

}

publicvoidsetlnitVal(intn){

initVal=n;

}

publicstaticvoidmain(String[]args){

Factorialff=newFactorial();

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

ff.setlnitVal(2*(i+l));

ff.result=Factorial(ff.initVal);

ff.print();

}//endfor()

}//endmain()

)//endpublicclassFactorial

publicclassFactorials{

privateintresult,initVal;

publicvoidprint(){

System,out.println(initVal+，z!=，z+result);

)

publicvoidsetlnitVal(intn){

initVal=n;

)

publicstaticvoidmain(StringE]args){

Factorialff=newFactorial();

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

ff.setlnitVal(2*(i+l));

ff.result=l;

for(intj=2;j<=ff.initVal;j++){

ff.result*=j;

)

ff.print();

}//endfor0

}//endmain()

}

〃習題3.5

publicclassMathRandomTest{

publicstaticvoidmain(String[]args){

intcount=0,MAXof100,MINofl00;

intnum,i;

MAXof100=(int)(100*Math.random());

MINof100=(int)(100*Math.random());

System.out.print(MAXof100+^〃)；

System.out.print(MINof100+，z〃)；

if(MAXof100>50)count++;

if(MINof100>50)count++;

if(MAXoflOO<MINoflOO){

num=MINofl00;

MINoflOO=MAXoflOO;

MAXof100=num;

}//endif()

for(i=0;i<98;i++){

num=(int)(100*Math.random());

System,out.print(mim+((i+2)%10=9?〃\n〃：”"));

if(num>MAXofl00){

MAXoflOO=num;

)

elseif(num<MINofl00){

MINof100=num;

)

if(num>50){

count++;

)

}//endfor()

System,out.printin(z，themaxof100randomintegersis'+MAXoflOO);

System,out.printlnC^theminof100randomintegersis//+MINoflOO);

System,out.printin(z，thenumberofrandommorethan50is"+count);

}//endmain()

}//endpublicclassMathRandomTest

〃習題3.7

publicclassPrintAst{

publicvoidprintAstar(){

System,out.print('*");

publicvoidprintSpace(){

System,out.print("");

publicstaticvoidmain(String[]args){

PrintAstpa=newPrintAst();

intinitNum=13;

for(inti=1;i<=initNum/2+1;i++){

for(intn=1;n<=i;n++){

pa.printSpace();

pa.printSpace();

for(intm=1;m<=initNum-2*i+2;m++)

pa.printSpace();

pa.printAstar();

)

System.out.printlnO;

}//endfor

if(initNum%2==0){

for(inti=1;i<=initNum/2;i++){

pa.printSpace();

pa.printSpace();

)

pa.printSpace();

pa.printAstar();

pa.printSpace();

pa.printAstar();

System.out.printlnO；

for(inti=initNum/2+2;i<=initNum;i++)

for(intn=1;n<=initNum-i+1;n++){

pa.printSpace();

pa.printSpace();

for(intm=l;m<=2*i-initNum;m++){

pa.printSpace0;

pa.printAstar();

)

System.out.printin();

}//endfor

System,out.printin();

1//endmainO

}//endpublicclassPrintAst

〃習題3.8

publicclassPrintTriag{

publicvoidprintAstar(){

System.out.print(〃*〃)；

}

publicstaticvoidmain(String[]args){

intinitLine=10;

intinitNum=10;

PrintTriagpt=newPrintTriag();

for(inti=0;i<initLine;i++){

for(intj=0;j<initNum-i;j++){

pt.printAstar();

)

System.out.printIn();

)

)//endmainO

)//endpublicclassPrintTriag

習題3.9

importjava.util.*;

publicclassMuitipieTable(

publicvoidprintFormula(inti,intj,intres){

System,out.print(j+〃*〃+j+〃=〃+res+〃〃);

}

publicstaticvoidmain(String[]args){

MultipleTablemt=newMultipleTableO;

intinitNum=9;

intres=0;

for(inti=l;i<=initNum;i++){

for(intj=l;j<=i;j++){

res=i*j;

mt.printFormula(i,j,res);

)

System.out.printin();

}//endfor

}//endmain()

}//endpublicclassMultipleTable

習題3,10

importjava.io.*;

publicclassHuiWen{

booleanisHuiWen(charstr[],intn){

intnet=0;

inti,j;

for(i=0,j=n-1;i<n/2;i++,j-){

if(str[i]==str[j]){

net++;

}//endif

}//endfor

if(net==(int)(n/2)){

returntrue;

}//endif

else{

returnfalse;

)

}//endbooleanisHuiWen(charstr[],intn)

publicstaticvoidmain(String[]args){

HuiWenhwl=newHuiWen0;

Stringpm二

try{

InputStreamReaderreader=newInputStreamReader(System,in);

BufferedReaderinput=newBufferedReader(reader);

System.out.printC'giveyourteststring:Xn^);

pm=input.readLineO;

System.out.printin(pm);

}//endtry

catch(lOExceptione){

System.out.print(e);

}//endcatch

booleanbw=hwl.isIIuiWen(pm.toCharArray0,pm.length());

if(bw==true){

System,out.printin("是回文");

)

else{

System.out.printIn("不是回文")；

}

}//endmain()

)//endpublicclassHuiWen

importjava.io.*;

publicclassHuiWen2{

Stringreverse(Stringwl){

Stringw2;

char[]strl=wl.toCharArray();

intlen=wl.length();

char[]str2=newchar[len];

for(inti=0;i<len;i++){

str2[i]=strl[len-l-i];

}

w2=newString(str2);

returnw2;

}

publicstaticvoidmain(String