1.根据这个头文件：
// golf.h -- for pe9-1.cpp const int Len = 40; struct golf {char fullname(Len);int handicap; }; // non-interactive version: // function sets golf structure to provided name, handicap // using values passed as arguments to the function void setgolf(golf & g, const char * name, int hc); // interactive version: // function solicits name and handicap from uaer // and sets the members of g to the valus entered // returns 1 if name is entered, 0 if name is empty string int setgolf(golf & g); // function resets handicap to new value void handicap(golf & g, int hc); // function displays contents of golf structure void showgolf(const golf &g);
注意到setgolf()被重载，可以这样使用其第一个版本：
golf ann; setgolf(ann, "Ann Birdfree", 24);
上述函数调用提供了存储在ann结构中的信息。可以这样使用其第二个版本：
golf andy; setgolf(andy);
上述函数将提示用户输入姓名和等级，并将它们存储在andy结构中。这个函数可以（但是不一定必须）在内部使用第一个版本。
根据这个头文件，创建一个多文件程序。其中的一个文件名为golf.cpp，它提供了与头文件中的原型匹配的函数定义；另一个文件应包含main()，并演示原型化函数的所有特性。例如，包含一个让用户输入的循环，并使用输入的数据来填充一个由golf结构组成的数组，数组被填满或用户将高尔夫选手的姓名设置为空字符串时，循环将结束。main()函数只使用头文件中原型化的函数来访问golf结构。
// golf.h
#include "golf.h"
#include <iostream>
#include <cstring>using namespace std;void setgolf(golf & g, const char * name, int hc){strcpy(g.fullname, name);g.handicap = hc;
}int setgolf(golf & g){cout << "Fullname:";cin.getline(g.fullname, Len);if(strlen(g.fullname) == 0){return 0;}cout << "Handicap:";cin >> g.handicap;cin.get();return 1;
}void handicap(golf & g, int hc){g.handicap = hc;
}void showgolf(const golf &g){cout << "Fullname:" << g.fullname << endl;cout << "Handicap:" << g.handicap << endl;
}#include "golf.h"
#include <iostream>const int size = 2;
using namespace std;int main(){golf ann;setgolf(ann, "Ann Birdfree", 24);showgolf(ann);golf andy;if(setgolf(andy) == 1)showgolf(andy);else{setgolf(andy, "Andy Bird", 50);handicap(andy, 40);showgolf(andy);} golf g[size];for(int i = 0; i < size; i++){cout << "#" << i + 1 << ":" << endl;int flag = setgolf(g[i]);if(flag == 0){setgolf(g[i], "kk", 3);}}for(int i = 0; i < size; i++){cout << "#" << i + 1 << "info:" << endl;showgolf(g[i]);}return 0;
}2.修改程序清单9.9：
//Listing 9.9 static.cpp // static.cpp -- using a static local variable #include <iostream> // constants const int ArSize = 10; // function prototype˜ void strcount(const char *str); int main() {using namespace std;char input[ArSize];char next;cout << "Enter a line:\n";cin.get(input, ArSize);while (cin){cin.get(next);while (next != '\n') // string didn't fit!cin.get(next); // dispose of remainder strcount(input);cout << "Enter next line (empty line to quit):\n";cin.get(input, ArSize);}cout << "Bye\n";return 0; } void strcount(const char *str) {using namespace std;static int total = 0;int count = 0;// static local variable // automatic local variablecout << "\"" << str << "\" contains ";while (*str++) // go to end of stringcount++;total += count;cout << count << " characters\n";cout << total << " characters total\n"; }
用string对象代替字符数组。这样，该程序将不再需要检查输入的字符串是否过长，同时可以将输入字符串同字符串“”进行比较，以判断是否为空行。
代码如下
//Listing 9.9 static.cpp
// static.cpp -- using a static local variable
#include <iostream>
#include <string>
// constants
//const int ArSize = 10;
// function prototype?
using namespace std;void strcount(string str);int main()
{
// char input[ArSize];string input;char next;cout << "Enter a line:\n";
// cin.get(input, ArSize);getline(cin, input);while (input.size()){
// cin.get(next);
// while (next != '\n') // string didn't fit!
// cin.get(next); // dispose of remainder strcount(input);strcount(input);cout << "Enter next line (empty line to quit):\n";getline(cin, input);}cout << "Bye\n";return 0;
}
void strcount(const string str)
{using namespace std;static int total = 0;int count;// static local variable // automatic local variablecout << "\"" << str << "\" contains ";count = str.size();total += count;cout << count << " characters\n";cout << total << " characters total\n";
}3.下面是一个结构声明：
struct chaff {char dross[20];int slag; };
编写一个程序，使用定位new运算符将一个包含两个这种结构的数组放在一个缓冲区中。然后，给结构的成员赋值（对于char数组，使用函数strcpy()），并使用一个循环来显示内容。一种方法是像程序清单9.10那样将一个静态数组用作缓冲区；另一种方法是使用常规new运算符来分配缓冲。
#include <iostream>
#include <cstring>
using namespace std;
struct chaff
{char dross[20];int slag;
};
int main(){chaff *ch = new chaff[2];strcpy(ch[0].dross, "aabbccddee");ch[0].slag = 12;strcpy(ch[1].dross, "abcde");ch[1].slag = 112;for(int i = 0; i < 2; i++){cout << "#" << i + 1 << ":" << endl;cout << "dross:" << ch[i].dross << endl;cout << "slag:" << ch[i].slag << endl;}return 0;
}4。请基于下面这个名称空间编写一个由3个文件组成的程序：
namespace SALES
{const int QUARTERS = 4;struct Sales{double sales [QUARTERS];double average;double max;double min;};// copies the lesser of 4 or n items from the array ar// to the sales member of s and computes and stores the // average, maximum, and minimum values of the entered items;// remaining elements of sales ,if any, set to 0void setSales(Sales & s,const double ar[],int n);// gathers sales for 4 quarters interactively,stores them// in the sales member of s and computes and stores the// average,maximum,and minimum valuesvoid setSales (Sales & s);// display all information in structure svoid showSales(const Sales & s);
}
第一个文件是一个头文件，其中包含名称空间：第二个文件是一个源代码文件，它对这个名称空间进行扩展，以提供这三个函数的定义；第三个文件声明两个Sales对象，并使用setSales（）的交互式版本为一个结构提供值，然后使用setSales（）的非交互式版本为另一个结构提供值。另外它还使用showSales（）来显示这两个结构的内容。
//sales.h-----头文件
namespace SALES
{const int QUARTERS = 4;struct Sales{double sales [QUARTERS];double average;double max;double min;};void setSales(Sales & s,const double ar[],int n);void setSales (Sales & s);void showSales(const Sales & s);
}//sales.cpp-----源代码文件
#include "sales.h"using namespace std;
namespace SALES
{void setSales(Sales &s, const double ar[], int n){double min = 0, max = 0, sum = 0;s.min = s.max = ar[0];for (int i = 0; i < n; i++){s.sales[i] = ar[i];sum += ar[i];if (ar[i] > max){max = ar[i];}if (ar[i] < min){min = ar[i];}}s.average = sum / n;}void setSales(Sales &s){cout << "Please enter 4 quarters for sales:" << endl;cout << "the 1 quarter :";cin >> s.sales[0];s.min = s.max = s.sales[0];for (int i = 1; i < 4; i++){cout << "the " << i << " quarter :";cin >> s.sales[i];if (s.max < s.sales[i]){s.max = s.sales[i];}if (s.min > s.sales[i]){s.min = s.sales[i];}}s.average = (s.sales[0] + s.sales[1] + s.sales[2] + s.sales[3]) / 4;}void showSales(const Sales &s){cout << "Display all information in sales : " << endl;cout << "The 4 quarters are $" << s.sales[0] << ", $" << s.sales[1] << ", $" << s.sales[2] << ", $" << s.sales[3] << endl;cout << "The average income is $" << s.average << endl;cout << "The maximum income is $" << s.max << endl;cout << "The minimum income is $" << s.min << endl;}
}//main.cpp
#include "sales.h"
#include <iostream>using namespace SALES;
int main()
{double arr[4] = {3.4, 5.6, 2.5, 6.1};Sales s1, s2;setSales(s1, arr, 4);showSales(s1);setSales(s2);showSales(s2);return 0;
}
