C++primer plus第六版课后编程题答案7.9

7.9

#include <iostream>
using namespace std;
const int SLEN=30;
struct student{
	char fullname[SLEN];
	char hobby[SLEN];
	int ooplevel;
};
int getinfo(student pa[],int n);
void display1(student st);
void display2(const student *ps);
void display3(const student pa[],int n);
void main79()
{
	cout<<"Enter class size: ";
	int class_size;
	cin>>class_size;
	while(cin.get()!='
')
		continue;
	student *ptr_stu=new student[class_size];
	int entered=getinfo(ptr_stu,class_size);
	for(int i=0;i<entered;i++)
	{
		display1(ptr_stu[i]);
		display2(&ptr_stu[i]);
	}
	display3(ptr_stu,entered);
	delete ptr_stu;
	cout<<"Done
";
	system("pause");
}
int getinfo(student pa[],int n)
{
	int count=0;
	for(int i=0;i<n;i++)
	{
		cout<<"Please enter the fullname:";
		cin>>pa[i].fullname;
		cout<<"
Please enter the hobby:";
		cin>>pa[i].hobby;
		cout<<"
Please enter the ooplevel:";
		cin>>pa[i].ooplevel;
		count++;
	}
	cout<<"
Enter end!";
	return count;

}

void display1(student st)	//按值传递
{
	cout<<"
display1:FullName:"<<st.fullname<<"
hobby:"<<st.hobby
		<<"
ooplevel:"<<st.ooplevel<<endl;
}

void display2(const student *ps) //传递地址，引用
{
	cout<<"
dispaly2:FullName:"<<ps->fullname<<"
hobby:"<<ps->hobby
		<<"
ooplevel:"<<ps->ooplevel<<endl;

}
void display3(const student pa[],int n)
{
	cout<<"
dispaly3:"<<endl;
	for(int i=0;i<n;i++)
		cout<<i<<"::FullName:"<<pa[i].fullname<<"
hobby:"<<pa[i].hobby
		<<"
ooplevel:"<<pa[i].ooplevel<<endl;
}