Java程序设计基础教程-杨佩理(源程序PDF课件)

1、Java程序设计基础教程-杨佩理（源程序&PDF课件）例4-1classAbc{staticintnum=0;voidcount(){num++;System.out.println(Thisisobject+num);}publicstaticvoidmain(String[]args){Abca=newAbc();Abcb=newAbc();Abcc=newAbc();a.count();b.count();c.count();System.out.println(Abc.num);}}例4-2classCircle{doubler;doublegetL(){return2*Math.PI*r;//Math.PI为圆周率}doublegetS(){returnMath.PI*r*r;}}例4-3classMyCal{staticintgetSum(intn){intsum=0;for(inti=1;i=n;i++)sum+=i;returnsum;}staticlonggetFac(intn){longfac=1;for(inti=1;i=n;i++)fac*=i;returnf。

2、ac;}}classTest{publicstaticvoidmain(String[]aa){System.out.println(MyCal.getSum(100)+\t+MyCal.getFac(10));}}例4-4classPerson{intsex;intsalary;voidemployed(){System.out.print(Workstate:);if(salary==0)System.out.println(nojob);elseSystem.out.println(job);}}classTest{publicstaticvoidmain(String[]aa){Personps=newPerson();ps.salary=300;ps.employed();ps.salary=0;ps.employed();}}例4-5classReferenceTest{publicstaticvoidmain(String[]args){Personp1=newPerson();//设对象为A，p1指向APersonp2=newPerson();//设对象为B，p2指向B。

3、p1.salary=1;p2.salary=2;System.out.println(p1.salary+\t+p2.salary);p1=p2;//p1重定向，也指向了p2指向的BSystem.out.println(p1.salary+\t+p2.salary);p1.salary=8;System.out.println(p1.salary+\t+p2.salary);}}例4-6classStar{staticvoidprint(charc,intn){for(inti=0;in;i++)System.out.print(c);}publicstaticvoidmain(String[]args){for(inti=0;i5;i++){print('',10-i);//输出10-i个空格print('*',2*i+1);//输出2i+1个星号System.out.println();}}}例4-7classTestCircle{publicstaticvoidmain(String[]args){Circlecc=newCircle();cc.r=3.5;System.out.。

4、println(cc.getL()+\t\t+cc.getS());}}例4-8classTestOL{intx;voidfunc(){System.out.println(noarg);}Stringfunc(inti){returnargis+i;}voidfunc(Strings){System.out.println(s);}publicstaticvoidmain(String[]a){TestOLc=newTestOL();c.func();c.func(c.func(100));}}例4-9classTestOL1{voidfunc(doublex){System.out.println(x+isdouble);}voidfunc(intx){System.out.println(x+isint);}publicstaticvoidmain(String[]a){TestOL1c=newTestOL1();c.func(1);//将调用voidfunc(intx)c.func(2.5);//将调用voidfunc(doublex)c.func(3.5f);//窄化转型，调。

5、用voidfunc(doublex)}}例5-1classCleverCircle{doubler;CleverCircle(doublex){r=x;}doublegetL(){return2*Math.PI*r;}doublegetS(){returnMath.PI*r*r;}}classTest{publicstaticvoidmain(String[]aa){CleverCirclecc=newCleverCircle(2);System.out.println(cc.getL()+\t\t+cc.getS());cc=newCleverCircle(3.5);System.out.println(cc.getL()+\t\t+cc.getS());}}例5-2classFlower{staticintnum=0;Flower(){num++;System.out.println(num+朵花开了！);}publicstaticvoidmain(String[]aa){newFlower();newFlower();newFlower();}}例5-3classMycal{st。

6、aticintsum(intn){ints=0;for(inti=0;i=n;i++)s+=i;returns;}staticintsum(intm,intn){ints=0;for(inti=m;i=n;i++)s+=i;returns;}publicstaticvoidmain(String[]aa){System.out.println(sum(100));System.out.println(sum(50,90));}}例5-4classNewFlower{staticintnum=0;NewFlower(){//第一个构造方法，无参num++;System.out.println(num+朵花开了！);}NewFlower(Stringcolor){//第二个构造方法，带字符串型参数num++;System.out.println(num+朵花开了........是+color+花！);}publicstaticvoidmain(String[]args){newNewFlower();//没有参数，调用第一个构造方法newNewFlower(红);//带参数，调用第二个构造。

7、方法newNewFlower(蓝);//带参数，调用第二个构造方法}}例5-5classRectangle{doublew;doubleh;Rectangle(doublex){//正方形，长宽相同w=h=x;}Rectangle(doublex,doubley){//矩形w=x;h=y;}doublegetS(){returnw*h;}}classTest{publicstaticvoidmain(String[]aa){System.out.println(newRectangle(2.3,4.5).getS());System.out.println(newRectangle(7.6).getS());}}例5-6classTag{Tag(intm){System.out.println(Tag(+m+));}}classCard{Tagt1=newTag(1);Card(){System.out.println(Card());t3=newTag(33);}Tagt2=newTag(2);voidf(){System.out.println(f());}Tagt3=newTag。

8、(3);}classTestInit2{publicstaticvoidmain(String[]aa){Cardt=newCard();t.f();}}例5-7classTestInitA{intx;Circley;booleanz;publicstaticvoidmain(String[]args){TestInitti=newTestInit();System.out.println(xis+ti.x);System.out.println(yis+ti.y);System.out.println(zis+ti.z);}}例5-8classTestInitC{intx=3;TestInitC(){x=5;}publicstaticvoidmain(String[]args){TestInitCt=newTestInitC();System.out.println(t.x);}}例5-9classTestInitD{TestInitD(inta){x=a;}publicstaticvoidmain(String[]args){System.out.println(newTestIn。

9、itD(5).x);}intx=3;}例5-10classTestInitE{Strings1=String1;TestInitE(){System.out.println(init);System.out.println(s2);}staticStrings2,s3;static{s2=String2;s3=String3;}}classTest{publicstaticvoidmain(String[]aa){System.out.println(CreatingnewTestInitE);newTestInitE();System.out.println(CreatingnewTestInitE);newTestInitE();}}例5-11classTestOL{intx;voidfunc(){System.out.println(noarg);}Stringfunc(inti){returnargis+i;}voidfunc(Strings){System.out.println(s);}publicstaticvoidmain(String[]a){TestOLc=newT。

10、estOL();c.func();c.func(c.func(100));}}例5-12classTestOL1{voidfunc(doublex){System.out.println(x+isdouble);}voidfunc(intx){System.out.println(x+isint);}publicstaticvoidmain(String[]a){TestOL1c=newTestOL1();c.func(1);//将调用voidfunc(intx)c.func(2.5);//将调用voidfunc(doublex)c.func(3.5f);//窄化转型，调用voidfunc(doublex)}}例5-13classThisTest{inta;ThisTest(inta){//参数与成员变量同名this.a=a;//成员变量a取得参数值a++;}publicstaticvoidmain(String[]args){System.out.println(newThisTest(5).a);//结果是？}}例5-14classTestB{inta;intb;Test。