2-4.cc

一个qt设计的教程

#include <iostream.h>

class car
{
public:
    car();
    ~car();
    void printdata();
    void printweight();
    void printtopspeed();
private:
    int *length;
    int *width;
    int *horsepower;
};

car::car()
{
 length=new int;
 width=new int;
 horsepower=new int;

 cout<<"define the length!\n:";
 cin>>*this->length;
 
 cout<<"define the width!\n:";
 cin>>*this->width;
 
 cout<<"define the horsepower!\n:";
 cin>>*this->horsepower;
}

car::~car()
{
 delete length;
 delete width;
 delete horsepower;
}

void car::printdata()
{
 cout<<"\n\nThis is the data:\n";
 cout<<"\nLength:"<<*this->length;
 cout<<"\nWidth:"<<*this->width;
 cout<<"\nHorse Power:"<<*this->horsepower;
 cout<<"\n";
}

void car::printweight()
{
 cout<<"Weight:"<<((*this->length)*(*this->width)*100);
}

void car::printtopspeed()
{
 if(*this->horsepower <= 200)
 {
  cout<<"\nTop Speed:"<<((*this->horsepower)*1.2)<<"\n";
 }
 if(*this->horsepower > 200)
 {
  cout<<"\nTop Speed:"<<((*this->horsepower)*0.8)<<"\n";
 }
}

class truck:public car
{
public:
   truck();
   ~truck();
   void printoreload();
private:
   int *ore_load;
};

truck::truck()
{
 ore_load = new int;

 cout<<"Define the ore load!\n";
 cin>>*this->ore_load;
}

truck::~truck()
{
 delete ore_load;
}

void truck::printoreload()
{
 cout<<"Ore load:"<<*this->ore_load<<"\n";
}

main()
{
 truck a_truck;
 a_truck.printdata();
 a_truck.printweight();
 a_truck.printtopspeed();

 a_truck.printoreload();
}