c++期末复习参考题

（一）读程序题1．类中包括其他类的对象成员，构造函数中要列出成员对象名带实参，生成该类对象时，要先调用成员对象的构造函数。

如果是成员对象的缺省构造函数可以不列，但生成该类对象时，仍要先调用成员对象的缺省构造函数。

1.如下程序运行时的输出结果是。

#include<iostream.h>class ONE{int c;public:ONE():c(0){cout<<1; }ONE(int n):c(n){cout<<3; }};classTWO:public ONE{ONE one1;ONE one2;public:TWO(int m):one2(m){cout<<5; }};void main(){TWO t(2);}1135二．派生类构造函数中要列出基类名带实参，生成派生类对象时，要先调用基类的构造函数，再调用派生类的构造函数。

冲突规则与支配规则。

2.如下程序运行时的输出结果是。

#include <iostream.h>class A{public:int x;A(){x=10;}A(int i){ x=i;}void Show(){cout<<"x="<<x<<'\t'<<"A\n";}};class B{public:int y;B(){y=30;}B(int i){ y= i;}void Show(){cout<<"y="<<y<<'\t'<<"B\n";}};class C: public A,public B{public:int y;C(inta,intb,int c):A(a),B(b+30){y= c;}void Show(){cout<<"y="<<y<<'\t'<<"C\n";}};void main(void) {C c1(20,30,40);c1.y=10;c1.Show (); c1.A::Show(); c1.B::Show();}三．派生类中包含对象成员，构造函数中要列出基类名带实参，再列出成员对象名带实参，生成派生类对象时，要先调用基类的构造函数，再调用成员对象的构造函数，最后调用派生类的构造函数。

如果是调用基类或成员对象的缺省构造函数可以不列，但生成派生类对象时，仍要先调用基类的缺省构造函数，再调用成员对象的缺省构造函数。

构造函数与析构函数调用顺序相反。

3．如下程序运行时的输出结果是。

#include <iostream.h>class A {public :A( ){ cout<<"A() \n";}~A( ){ cout<<"~A() \n";}};class B {public:B( ){ cout<<"B()\n"; }~B( ){ cout<<"~B() \n"; }};class C: public B,public A {A a;public :C( ) { cout<<"C() \n"; }~C( ) { cout<<"~C()\n"; }};void main( ) {C c1;}4．如下程序运行时的输出结果是。

#include <iostream.h>class A{public:A(){cout<<'A'<<endl;}};class T{A a;public:T(){cout<<'T'<<endl;}};class X:public A{T t;public:X(){cout<<'X'<<endl;}};void main(){X ob;}三．虚基类5.下列程序运行后的输出结果是。

#include<iostream.h>class A{public:A(){ cout<<"A \n"; }~A(){ cout<<"~A \n"; }};class B:virtual public A{public:B():A(){ cout<<"B \n"; }~B(){ cout<<"~B \n"; }};class C:public virtual A{public:C():A(){ cout<<"C \n"; }~C(){ cout<<"~C \n"; }};class D:public C,public B{public:D():B() , C(), A(){ cout<<"D \n"; }~D(){ cout<<"~D \n"; }};void main(){ D d1; }6. 下列程序的输出结果是。

#include<iostream.h>class A{public:A(){ cout<<"A \n"; }~A(){ cout<<"~A \n"; }};class B: public A{public:B():A(){ cout<<"B \n"; }~B(){ cout<<"~B \n"; }};class C:public A{public:C():A(){ cout<<"C \n"; }~C(){ cout<<"~C \n"; }};class D:public C,public B{public:D():B() , C(){ cout<<"D \n"; }~D(){ cout<<"~D \n"; }};void main(){ D d1; }7. 下列程序的输出结果是。

#include<iostream.h>#include<string.h>class B{charstr[20];public:B (char *s="default"){strcpy(str,s); cout<<str<<endl; }};class Ih1:public virtual B{char str1[20];public:Ih1(char *s1, char *s2): B (s1){strcpy(str1,s2);cout<<str1<<endl; }};class Ih2: public virtual B{char str2[20];public:Ih2(char *s1, char *s2): B (s1){ strcpy(str2,s2);cout<<s2<<endl; } };class Ih3: public Ih1, public Ih2{char str3[20];public:Ih3(char *s1, char *s2, char *s3, char *s4): Ih1(s1,s2),Ih2(s1,s3) { strcpy(str3,s4); cout<<str3<<endl; }};void main(){Ih3 h3("abc","def","ghi","jkl");}四．运行时多态8．下列程序的输出结果是。

#include <iostream.h>class A{public:virtual void f1( ) {cout<<"类A中的f1\n";}virtual void f2( ) {cout<<"类A中的f2\n";}void f3( ) {cout<<"类A中的f3\n";}};class B:public A{public:void f1( ) {cout<<"类B中的f1\n";}void f2(int) {cout<<"类B中的f2\n";}void f3( ) {cout<<"类B中的f3\n";}};void main( ){A a1,*p;B b1;p=&b1;p->f1( ); p->f2( ); p->f3( );}9. 如下程序运行时的输出结果是。

#include<iostream.h>class A{public:virtual void f( ){cout<<1; }void g( ){ cout<<2; }};class B: public A {public:virtual void f( ){ cout<<3; }void g( ){ cout<<4; }};void show( A &a) { a.f( ); a.g( ); }void print(A *p){p->f(); p->g();}void main( ){B b;show(b);print(&b); }10.如下程序运行时的输出结果是。

#include <iostream.h>#include <string.h>class P{public:P(char *s){name=new char[strlen(s)+1];strcpy(name,s);}virtual void print(){cout<<"I am "<<name<<"\n";}~P(){delete []name;}protected:char *name;};class S:public P{public:S(char *s,double g):P(s){gj=g;}void print(int k){cout<<name<<" is "<<gj*k<<endl;}private:doublegj;};classF:public P{public:F(char *s,int n):P (s){pub=n;}void print() {cout<<name<<" published "<<pub<<" books.\n";}private:int pub;};void main(){int a=25;P *p;P pers("Zhang");S stud("Wang",3.6);Fprof("Li",4);p=&pers;p->print();p=&stud;p->print();p=&prof;p->print();stud.print(a);}11.如下程序运行时的输出结果是。