1、第八次實驗實驗1：中國人、北京人和美國人1.實驗要求：編寫程序模擬中國人、美國人是人，北京人是中國人。除主類外，程序中還有4個類：People、ChinaPeople、AmericanPeople和BeijingPeople 類。要求如下：（1） People類有權(quán)限是protected的double型成員變量height和weight，以及public void speakHello（）、public void averageHeight（）和public void averageWeight（）方法。（2） ChinaPeople類是People的子類，新增了public void ave

2、rageHeight（）和public voidaverageWeight（）方法。（3） AmericanPeople類是People的子類，新增方法public void AmericanBoxing（） 。要求AmericanPeople重寫父類的public void speakHello（）、public void averageHeight（）和public void averageWeight（）方法。（4） BeijingPeople類是ChinaPeople的子類，新增public void beijingOpera（）方法。2.實驗代碼：/People.javapublic

3、 class People protected double weight,height;public void speakHello() System.out.println(yayayaya);public void averageHeight() height=173;System.out.println(average height:+height);public void averageWeight() weight=70;System.out.println(average weight:+weight);/ChinaPeople.javapublic class ChinaPeo

4、ple extends People public void speakHello() System.out.println(您好);public void averageHeight() height=168.78;System.out.println(中國人的平均身高：+height+厘米);public void averageWeight() weight=65;System.out.println(中國人的平均體重：+weight+千克);public void chinaGongfu() System.out.println(坐如鐘，站如松，睡如弓);/AmericanPeople

5、.javapublic class AmericanPeople extends People public void speakHello () System.out.println(How do you do);public void averageHeight() height=176;System.out.println(Americans average height:+height+厘米);public void averageWeight() weight=75;System.out.println(Americans average weight:+weight+ kg);pu

6、blic void americanBoxing() System.out.println(直拳，勾拳，組合拳);/BeijingPeople.javapublic class BeijingPeople extends ChinaPeople public void averageHeight() height=172.5;System.out.println(北京人的平均身高:+height+厘米);public void averageWeight() weight=70;System.out.println(北京人得平均體重：+weight+千克);public void beijin

7、gOpera() System.out.println(花臉、青衣、花旦和老生);/Example.javapublic class Example public static void main(String arg) ChinaPeople chinaPeople=new ChinaPeople();AmericanPeople americanPeople=new AmericanPeople();BeijingPeople beijingPeople=new BeijingPeople();chinaPeople.speakHello();americanPeople.speakHel

8、lo();beijingPeople.speakHello();chinaPeople.averageHeight();americanPeople.averageHeight();beijingPeople.averageHeight();chinaPeople.averageWeight();americanPeople.averageWeight();beijingPeople.averageWeight();chinaPeople.chinaGongfu();americanPeople.americanBoxing();beijingPeople.beijingOpera();bei

9、jingPeople.chinaGongfu();3.實驗結(jié)果：4.實驗分析：(1) 方法重寫時要保證方法的名字、類型、參數(shù)的個數(shù)和類型同父類的某個方法完全想同。這樣，子類繼承的方法才能被隱藏。(2) 子類在重寫方法時，如果重寫的方法是static方法，static關(guān)鍵字必須保留；如果重寫的方法是實例方法，重寫時不可以用static修飾。(3) 如果子類可以繼承父類的方法，子類就有權(quán)利重寫這個方法，子類通過重寫父類的方法可以改變父類的具遺體行為。5.實驗后的練習(xí)：People類中的public void speakHello() public void averageHeight() publ

10、ic void averageWeight() 三個方法的方法體中的語句是否可以省略。答：可以省略，因為省略后結(jié)果沒有變化 實驗2：銀行計算利息1.實驗要求：假設(shè)銀行bank已經(jīng)有了按整年year計算利息的一般方法，其中year只能取正整數(shù)。比如，按整年計算的方法：Double computerInternet()Interest=year*0.35*saveMoney;Return interest;建設(shè)銀行constructionBank是bankde 子類，準備隱藏繼承的成員變量year，并重寫計算利息的方法，即自己聲明一個double型的year變量。要求constructionban

11、k和bankofDalian類是bank類的子類，constructionbank和bankofdalian都使用super調(diào)用隱藏的按整年計算利息的方法。2.實驗代碼：/Bank.javapublic class Bankint savedMoney;int year;double interest;double interestRate=0.29;public double computerInterest()interest=year*interestRate*savedMoney;return interest;public void setInterestRate( double r

12、ate)interestRate=rate;/ ConstructionBank.javapublic class ConstructionBank extends Bankdouble year;public double computerInterest()super.year=(int)year;double r=year-(int)year;int day=(int)(r*1000);double yearInterest=puterInterest();double dayInterest=day*0.0001*savedMoney;interest=yearInterest+day

13、Interest;System.out.printf(%d元存在建設(shè)銀行%d年零%d天的利息:%f元n,savedMoney,super.year,day,interest);return interest;/ BankOfDalian.javapublic class BankOfDalian extends Bank double year; public double computerInterest() super.year=(int)year; double r=year-(int)year; int day=(int)(r*1000); double yearInterest=pu

14、terInterest(); double dayInterest=day*0.00012*savedMoney; interest=yearInterest+dayInterest; System.out.printf(%d元存在大連銀行%d年零%d天的利息:%f元n,savedMoney,super.year,day,interest); return interest; / SaveMoney.javapublic class SaveMoneypublic static void main(String args)int amount=8000;ConstructionBank ban

15、k1=new ConstructionBank();bank1.savedMoney=amount;bank1.year=8.236;bank1.setInterestRate(0.035);double interest1=puterInterest();BankOfDalian bank2=new BankOfDalian();bank2.savedMoney=amount;bank2.year=8.236;bank2.setInterestRate(0.035);double interest2=puterInterest();System.out.printf(兩個銀行利息相差%f元n

16、,interest2-interest1);3.實驗結(jié)果：4.實驗分析：（1） 子類不繼承父類的構(gòu)造方法，因此子類在其構(gòu)造方法中需使用super來調(diào)用父類的構(gòu)造方法，并且super必須是子類構(gòu)造方法中的頭一條語句。（2） 當(dāng)super調(diào)用被隱藏的方法時，該方法中出現(xiàn)的成員變量是被子類隱藏的成員變量或繼承的成員變量。5.實驗后的練習(xí)：參照建設(shè)銀行或大連銀行，在編寫一個商業(yè)銀行，讓程序輸出8000元存在商業(yè)銀行8年零236天的利息。/Bank.javapublic class Bankint savedMoney;int year;double interest;double interestRa

17、te=0.29;public double computerInterest()interest=year*interestRate*savedMoney;return interest;public void setInterestRate( double rate)interestRate=rate;/ CommercialBankpublic class CommercialBank extends Bank double year; public double computerInterest() super.year=(int)year; double r=year-(int)yea

18、r; int day=(int)(r*1000); double yearInterest=puterInterest(); double dayInterest=day*0.00012*savedMoney; interest=yearInterest+dayInterest; System.out.printf(%d元存在商業(yè)銀行%d年零%d天的利息:%f元n,savedMoney,super.year,day,interest); return interest; / SaveMoney.java public class SaveMoneypublic static void main

19、(String args)int amount=8000;CommercialBank bank=new CommercialBank();bank.savedMoney=amount;bank.year=8.236;bank.setInterestRate(0.035);double interest=puterInterest();實驗3：公司支出的總薪水1.實驗要求：要求有一個abstract類，類名為Employee。Employee的子類有YearWorker、MonthWorker、WeekWorker。YearWorker對象按年領(lǐng)取薪水，MonthWorker按月領(lǐng)取薪水、We

20、ekWorker按周領(lǐng)取的薪水。Employee類有一個abstract方法：public abstract earnings();子類必須重寫父類的earings()方法，給出各自領(lǐng)取報酬的具體方式。有一個Company類，該類用Employee對象數(shù)組作為成員，Employee對象數(shù)組的單元可以是YearWorker對象的上轉(zhuǎn)型對象、MonthWorker獨享的上轉(zhuǎn)型獨享或weekworker對象的上轉(zhuǎn)型獨享。程序能輸出Company對象一年需要支付的薪水總額。2.實驗代碼：abstract class Employeepublic abstract double earnings();c

21、lass YearWorker extends Employeepublic double earnings()return 12000;class MonthWorker extends Employeepublic double earnings()return 12*2300;class WeekWorker extends Employeepublic double earnings()return 52*780;class CompanyEmployee employee;double salaries=0;Company(Employee employee)this.employee=employee;public double salariesPay()salaries=0;for(int i=0;iemployee.length;i+)salaries=salaries+employeei.earnings();return salaries;public class CompanySalarypublic static void main(String args)Employee employee=new Employee29;for(int i=0;iemployee