求助!!3题改错的和10题给出程序写结果的。急。。。。。在线等。麻烦高手了!
6. 找出下面程序中的错误并说明理由。class base{
protected:
int p;};
void fun()
{
base b;
int x=b.p;
}
7. 分析下列程序,指出错误的地方并予以改正。
class base{
public:
int b;};
class base1:public base{?}
class base2:public base{?}
class derived:public base1:public base2{
public:
int f();
};
main()
{
derived d;
d.b();
d.base::b;
}
8. 如果希望下列程序的运行结果如下,请将程序补充完整。
Base¢s cons.
Derived¢s cons.
Derived¢s des.
Base¢s des.
class Base{
public:
Base(){cout<< “Base¢s cons.”<<endl;}
{cout<< “Base¢s des.”<<endl;}
};
class Derived:public Base{
public:
Derived(){cout<< “Derived¢s cons.”<<endl;}
~Derived(){cout<< “Derived¢s des.”<<endl;}
};
void main()
{ Base *ptr=
delete ptr;}
1. 写出下列程序的运行结果
#include <iostream.h>
int i=15;
void main()
{
int i;
i=100;
::i=i+1;
cout<<::i<<endl;
}
2. 写出下列程序的运行结果
class Person{
public:
Person(){cout<< “Constructor of Person”<<endl;}
~Person(){cout<< “Destructor of Person”<<endl;}
};
class Student:public Person{
public:
Student(){cout<< “Constructor of Student”<<endl;}
~Student(){cout<< “Destructor of Student”<<endl;}
};
class Teacher:public Person{
public:
Teacher(){cout<< “Constructor of Teacher”<<endl;}
~Teacher(){cout<< “Destructor of Teacher”<<endl;}
};
void main()
{
Student s;
Teacher t;
}
3. 写出下列程序的运行结果。
#include <iostream.h>
int square(int i) {return i*i;}
float square(float i) {return i*i;}
double square(double i) {return i*i;}
int main()
{ int i=12;
float f=3.0;
double d=5.0;
cout<<i<<'*'<<i<<'='<<square(i)<<'\n';
cout<<f<<'*'<<f<<'='<<square(f)<<'\n';
cout<<d<<'*'<<d<<'='<<square(d)<<'\n';
return 0;
}
4. 写出下面程序运行的结果。
#include <iostream.h>
class B{
public:
B(){cout<< “class B”<<endl;}
};
class X:virtual public B
{
public:
X(){cout<< “class X”<<endl;}
};
class Y:virtual public B
{
public:
Y(){cout<< “class Y”<<endl;}
};
class D:public X,public Y
{
public:
D(){cout<< “class D”<<endl;}
};
void main()
{ D obj; }
5. 写出下面程序运行的结果。
#include <iostream.h>
int main()
{
int *p;
p=new int(99);
cout<<*p++;
delete --p;
return 0;
}
6. 写出下面程序运行的结果。
#include <iostream.h>
class Base{
public:
virtual int func() {return 0;}
};
class Derived:public Base{
public:
int func() {return 100;}
};
void main()
{
Derived d;
Base &b=d;
cout<<b.func()<<endl;
cout<<b.Base::func()<<endl;
}
7. 写出下面程序运行的结果。
class timer{
int seconds;
public:
timer() {seconds=0;}
timer(char *t) {seconds=atoi(t);}
timer(int t) {seconds=t;}
timer(int min,int sec) {seconds=min*60+sec;}
int gettime() {return seconds;}
};
main()
{
timer a,b(10),c(“20”),d(1,10);
cout<<“seconds1=“<<a.gettime()<endl;
cout<<“seconds2=“<<b.gettime()<endl;
cout<<“seconds3=“<<c.gettime()<endl;
cout<<“seconds4=“<<d.gettime()<endl;
return 0;
}
8. 写出下面程序运行的结果。
class point{
int x,y;
public:
point(int a,int b) {x=a; y=b;}
point(const point &p) {x=2*p.x; y=2*p.y;}
void print() {cout<<x<<“ “<<y<<endl;}
};
main()
{
point p1(30,40);
point p2(p1);
p1.print();
p2.print();
return 0;
}
9. 写出下面程序运行的结果。
class ab{
private:
int a;
public:
ab( );
};
ab::ab()
{
cout<<“initialized \n”;
a=10;
}
void main()
{ ab s; }
10. 写出下面程序运行的结果。
#include <iostream.h>
class test{
private:
int num;
public:
test();
int getint() {return num;}
~test();
};
test::test() {num=0;}
test::~test() {cout<<″Destructor is active″<<endl;}
void main()
{
test x[3];
cout<<″Exiting main″<<endl;
}