面向对象技术与C++考试A卷答案

一、程序填空题(共5题，每空2分，共30分)1、#include<iostream.h>classA{ (1) voidf(inti){cout<<i<<'\t';}voidg(){cout<<"g\n";}};classB:privateA{public:voidh(){cout<<"h\n";} (2) };voidmain(){Bd;d.f(6);d.h();}输出：6h参考答案：(1)public:(2)voidf(inti){A::f(i);}//cout<<i<<'\t';}2、#include<iostream.h>classp_class{intnum;public:voidset_num(intval){num=val;}voidshow_num();};voidp_class::show_num(){cout<<num<<'\t';}voidmain(){p_classob[3],*p;for(inti=0;i<3;i++)ob[i].set_num((i+1)*10); (3) ;p->show_num(); (4) ;p->show_num(); (5) ;p->show_num();}输出：203010参考答案：(3)p=&ob[1](4)p=&ob⑵(5)p=&ob[0]3、#include<iostream.h>classTdate{intmonth;intday;intyear;intIsLeapYear(){return(year%4==0&&year%100!=0)||(year%400==0);} (6) voidSet(intm,intd,inty){month=m;day=d;year=y;} (7) ;}; (8) Print(){cout<<month<<"/"<<day<<"/"<<year<<endl;if(IsLeapYear())cout<<"ThisyearIsleapyear.\n";elsecout<<"ThisyearIsnotleapyear.\n";}voidmain(){Tdatea;a.Set(2,4,2000);a.Print();}参考答案：(6)public:(7)voidPrint()(8)voidTdate::4、#include<iostream.h>classTime{public:Time(inth,intm){hours=h;minutes=m;}voidTime12(); (9) Time24(Timetime);private:inthours,minutes;}; (10) Time12(){if(hours>12){cout<<hours-12<<":"<<minutes<<"PM\n";}elsecout<<hours<<":"<<minutes<<"AM\n";}voidTime24(Timetime){cout (11) }voidmain(){TimeT1(20,30),T2(10,45);T1.Time12();Time24(T1);T2.Time12();Time24(T2);}输出：8:30PM20:3010:45AM10:45参考答案：(9)friendvoid(10)voidTime::(11)<<time.hours<<":"<<time.minutes<<endl;5、已知一维数组类ARRAY的定义如下，构造函数的作用是把参数n的值赋给s,给v动态分配长度为n的数组空间，接着利用数组参数a初始化v所指向的数组。ARRAY与普通一维数组区别是：其重载的运算符［］要对下标是否越界进行检查。#include"iostream.h"#include"stdlib.h"classARRAY{int*v; //指向存放数组数据的空间ints; //数组大小public:ARRAY(inta[],intn);~ARRAY(){delete[]v;}intsize(){returns;}int&operator[](intn);};ARRAY::ARRAY(inta[],intn){if(n<=0){v=NULL;s=0;return;}s=n;TOC\o"1-5"\h\zv= (12) ;for(inti=0;i<n;i++) (13) ;} (14) operator[](intn)//[]的运算符成员函数定义{if(n<0lln>=s){cerrvv"下标越界！";exit(1);}return (15) ;}参考答案：(12)newint[s](13)v[i]=a[i](14)int&ARRAY::(15)v[n]二、写出程序的运行结果(共7题，每题5分，共35分)1、 #includeviostream.h>intf(inta[][3],introw,intcol){inti,j,t=1;for(i=0;ivrow;i++)for(j=0;jvcol;j++){a[i][j]++;if(i==j)t*=a[i][j];}returnt;}voidmain(){inta[][3]={0,1,2,3,4,5,6,7,8};coutvvf(a,3,3)vvendl;}参考答案：452、 #includeviostream.h>classtest{private:intnum;public:test();intgeint("returnnum;}~test();}；test::test(){cout<<"constructorisactive!"vvendl;num=0;}test::~test(){coutvv"Destructorisactive!"vvendl;}voidmain(){testx[2];coutvv"Exitingmain"vvendl;}；3FistriJictorisactiue?□nstruGtorIsactive!:xitmaintestructorisactive!testructorisactive!'ressanvheytrcontinue3、#includeviostream.h>classBasel{public:Base1(inti){coutvv"Baselconstruct"vvivvendl;}};classBase2{public:Base2(intj){coutvv"Base2construct"vvjvvendl;}};classA:publicBasel,publicBase2{public:A(inta,intb,intc,intd):Base2(b),Basel(c),b2(a),bl(d){coutvv"Aconstruct:"vva+b+c+dvvendl;}private:Baselbl;Base2b2;}；voidmain(){Aobj(1,2,3,4);}c：\.苯:迂+*UKt**IDetHjqKi4.raa"Estselconstruct3EaseSconstruct2Baselconstruct4fiase2construct1Actinstyuct：10Pressftn^i tocontinue4、#include<iostream.h>classLocation{public:Location(intxx=0,intyy=0){X=xx;Y=yy;cout<<"ConstructorObjectAn";}Location(Location&p) 〃复制构造函数{X=p.X;Y=p.Y;cout<<"Copy_constructorcalled."<<endl;}-Location。{cout<<X<< <<Y<<"Objectdestroyed."<<endl;}intGetX(){returnX;}intGetY(){returnY;}private:intX,Y;};voidf(Locationp){cout<<"Funtion:"<<p.GetX()<<","<<p.GetY()<<endl;}voidmain(){LocationA(1,2);f(A);}ConetpuctopObject_Copy-ConstiMJictot1calledPuntion=1,2ir2Objectdest^Gyed-1,2ObjectdestK'oved-Pressanyheytocontinue5、#include<iostream.h>classA{public:A(){cout<<"callA()\n";}virtual~A(){cout<<"call~A()\n";}};classB:publicA{char*buf;public:B(){buf=newchar[100];cout<<"callB()\n";}~B(){delete[]buf;cout<<"call~B()\n";}}；voidmain(){A*p=newB;deletep;}jail 、'fill 、沖>;all啪<>fress&n_ykeytoconti.nue6、 #include"iostream.h"voidmain(){inta[3]⑶={1234^,6,7,8,9};coutvv*(a[1]+2);}参考答案：67、 #includeviostream.h>classBclass{public:Bclass(inti,intj){x=i;y=j;}virtualintfun(){return0;}intgetx(){returnx;}intgety(){returny;}protected:intx,y;};classIclass:publicBclass{public:Iclass(inti,intj,intk):Bclass(i,j){z=k;}intfun(){return(x+y+z)/3;}intgetz(){returnz;}private:intz;};voidmain(){Iclassobj(2,4,10);Bclasspl=obj;cout<<p1.fun()<<endl;Bclass&p2=obj;cout<<p2.fun()<<endl;cout<<p2・Bclass::fun()<<endl;Bclass*p3=&obj;cout<<p3->fun()<<endl;cout«((Idass*)p3)->getz()«endl;}三编程题(1、2每小题10分，第3题15分，共35分)：1、用面向对象的方法，编程实现求100~300以内的所有素数。参考答案#includeviostream・h>#include"math.h"classA{intm,n;public:A(intmm=100,intnn=300){m=mm;n=nn;}voidsushu();};voidA::sushu(){intx,i,flag;for(x=m;x<=n;x++){flag=1; /*设置标志*/for(i=2;i<=sqrt(x);i++)if(x%i==0){flag=0;break;} /*改变标志*/if(flag==0)continue; /*判断标志*/coutvvxvv"\t";}};voidmain(){Aa(100,300);a.sushu();}2、利用静态数据成员的概念，编写一个类，可以统计目前存在多少个该类的对象，并在主程序中使用这个类。#include"iostream.h"classcounter{staticint num;//(1分)public:counter(){num=num+1;cout<<num<<"";}//每创建一个对象num加1//(2分)~counter(){num=num-1;cout<<num<<"";}//每删除一个对象num减1//(2分)};int counter::num=0;//(2分)voidmain(){cout<<endl;countera,b,c; cout<<endl;}//(3分)3、定义一个字符串类String，分别用成员函数和友元函数重载运算符“+”实现2个字符串连接。#include"iostream.h"#include<str