4.6

#include <iostream>
#include <string>
using namespace std;
struct CandyBar
{string name;double weight;int kaluli;
};
void show(CandyBar &c);//按值传递和引用传递均可
void main46()
{CandyBar cb[3]={{"one",1.8,10},{"two",2.9,30},{"three",5.0,60}};for(int i=0;i<3;i++)show(cb[i]);}
void show(CandyBar &c)
{cout<<"name="<<c.kaluli<<" ,weight="<<c.weight<<" ,kaluli="<<c.kaluli<<endl;}

4.7

#include <iostream>
#include <string>
using namespace std;
struct Pizza
{
string name;
double d;
double w;
};
Pizza get(Pizza &p);
void show(const Pizza &p);void main47()
{Pizza p;for(int i=0;i<3;i++){get(p);show(p);}
}Pizza get(Pizza &p)    //若不使用引用变量，返回时返回的是一个未知的变量
{cout<<"Enter the Pizza name:";string name;getline(cin,name);p.name=name;cout<<"\n Enter the d:";double d;cin>>d;p.d=d;cout<<endl<<"Enter the weight:";double w;cin>>w;p.w=w;return p;
}
void show(const Pizza &p)
{cout<<"name="<<p.name<<" ,d="<<p.d<<" ,weight="<<p.w<<endl;cin.get();}

4.8

#include <iostream>
#include <string>
using namespace std;
struct Pizza
{
string name;
double d;
double w;
};
Pizza *get(Pizza *p);
void show(const Pizza *p);void main48()
{Pizza *p;p=new Pizza();for(int i=0;i<3;i++){get(p);show(p);//delete p;}delete p;//delete p;}Pizza *get(Pizza *p)    //若不使用引用变量，返回时返回的是一个未知的变量
{//p=new Pizza();cout<<"Enter the Pizza name:";string name;getline(cin,name);p->name=name;cout<<"\n Enter the d:";double d;cin>>d;p->d=d;cout<<endl<<"Enter the weight:";double w;cin>>w;p->w=w;return p;
}
void show(const Pizza *p)
{cout<<"name="<<p->name<<" ,d="<<p->d<<" ,weight="<<p->w<<endl;cin.get();}

4.9

#include <iostream>
#include <string>
using namespace std;
struct CandyBar
{string name;double weight;int kaluli;
};
void show(const CandyBar *c);
void main49()
{CandyBar *c=new CandyBar[3];//结构体数组定义方法for(int i=0;i<3;i++,c++){c->name="String"+i;c->weight=i;c->kaluli=i*10;show(c);}delete []c;}void show(const CandyBar *c)
{cout<<"name="<<c->kaluli<<" ,weight="<<c->weight<<" ,kaluli="<<c->kaluli<<endl;}

4.10

#include <iostream>
#include <array>
using namespace std;void main410(){array <int,3> arr;int sum=0;for(int i=0;i<3;i++){cout<<"Enter the "<<i+1<<" time :";cin>>arr[i];sum+=arr[i];}double pinjun;cout<<"平均成绩为："<<sum*1.0/3<<endl;cin.get();}