头文件 golf.h
1 //golf.h --for pe9-1.cpp 2 3 const int Len = 40; 4 struct golf 5 { 6 char fullname[Len]; 7 int handicap; 8 }; 9 10 void setgolf(golf &g, const char *name, int hc); 11 12 int setgolf(golf &g); 13 14 void handicap(golf &g, int hc); 15 16 void showgolf(const golf &g);
golf.cpp
1 #include<iostream> 2 #include"golf.h" 3 using namespace std; 4 void setgolf(golf &g, const char *name, int hc) 5 { 6 strcpy_s(g.fullname, name); //注意：char型数组要用strcpy（） 7 g.handicap = hc; 8 } 9 10 int setgolf(golf &g) 11 { 12 cout << "Enter the fullname: "; 13 cin.get(g.fullname,Len); 14 if (g.fullname[0] == '\0') //若姓名是空字符串则返回0 15 return 0; 16 cin.get(); //跳过换行符 17 cout << "Enter the handicap: "; 18 cin >> g.handicap; 19 cin.get(); //跳过换行符 20 return 1; 21 } 22 23 void handicap(golf &g, int hc) 24 { 25 g.handicap = hc; 26 } 27 28 void showgolf(const golf &g) 29 { 30 cout << "Golfer: " << g.fullname << endl; 31 cout << "Handicap: " << g.handicap << endl; 32 }
main.cpp
1 #include <iostream> 2 #include"golf.h" 3 using namespace std; 4 5 const int cnt = 5; 6 7 int main() 8 { 9 golf ann; 10 setgolf(ann, "Ann Birdfree", 24); 11 showgolf(ann); 12 cout << endl; 13 14 golf andy[cnt]; 15 cout << "输入" << cnt << "名球队成员信息：" << endl; 16 int i; 17 for(i=0;i<cnt;i++) 18 { 19 if (setgolf(andy[i]) == 0) 20 break; 21 } 22 cout << endl; 23 for (int j = 0; j < i; j++) 24 { 25 showgolf(andy[j]); 26 } 27 cout << endl; 28 29 handicap(ann, 88); 30 showgolf(ann); 31 32 system("pause"); 33 return 0; 34 }
2、修改程序清单9.9: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,比判断是否为空行
修改前
1 #include<iostream> 2 using namespace std; 3 4 const int Size = 10; 5 void strcount(const char *str); 6 7 int main() 8 { 9 char in[Size]; 10 char next; 11 cout << "Enter a line:" << endl; 12 cin.get(in, Size); //cin.get(in, Size)将一直读取，直到到达行尾或读取了Size-1个字符为止，把换行符留在输入队列 13 while (cin) // ==while(!cin.fail()),即读入流成功 14 { 15 cin.get(next); //用cin.get(next)读取行输入后的字符，如果next是换行符，则说明cin.get(in, Size)读取了整行； 16 while (next != '\n') //如果next不是换行符，则说明行中还有字符没有被读取，通过while循环丢弃余下的字符 17 cin.get(next); 18 strcount(in); 19 cout << "Enter next line (empty line to quit):\n"; 20 cin.get(in, Size); 21 } 22 cout << "Bye!" << endl; 23 system("pause"); 24 return 0; 25 } 26 27 void strcount(const char *str) //const表示str指针不能修改指向的内容（不过指针可以指向另外一块内容） 28 { 29 static int total = 0; //static使total成为静态持续性，无链接性变量，首次初始化后，其值一直存在（即第二次调用strcount函数时，total的值不会再次初始化） 30 int count = 0; 31 cout << "\"" << str << "\" contains "; 32 while (*str++) 33 count++; 34 total += count; 35 cout << count << " characters\n"; 36 cout << total << " characters total!\n"; 37 }
修改后
1 #include<iostream> 2 #include<string> 3 using namespace std; 4 5 const int Size = 10; 6 void strcount(const string &str); 7 8 int main() 9 { 10 string in; 11 cout << "Enter a line:" << endl; 12 getline(cin,in); 13 while (in!=" ") 14 { 15 strcount(in); 16 cout << "Enter next line (empty line to quit):\n"; 17 getline(cin, in); 18 } 19 cout << "Bye!" << endl; 20 system("pause"); 21 return 0; 22 } 23 24 void strcount(const string &str) 25 { 26 static int total = 0; 27 int count; 28 cout << "\"" << str << "\" contains "; 29 count = str.length(); 30 total += count; 31 cout << count << " characters\n"; 32 cout << total << " characters total!\n"; 33 }
3.下面是一个结构声明
1 #include<iostream> 2 #include<string> 3 using namespace std; 4 5 struct chaff 6 { 7 char dross[20]; 8 int slag; 9 }; 10 11 int main() 12 { 13 //将一个静态数组用作缓冲区 14 char buffer[500]; 15 chaff *p; 16 p = new (buffer) chaff[2]; 17 for (int i = 0; i < 2; i++) 18 { 19 cout << "Enter dross: "; 20 char dross[20]; 21 cin.get(dross, 20); 22 strcpy_s(p[i].dross, dross); 23 cout << "Enter slag: "; 24 cin >> p[i].slag; 25 cin.get(); 26 } 27 for (int i = 0; i < 2; i++) 28 { 29 cout << "Dross: " << p[i].dross << endl; 30 cout << "Slag: " << p[i].slag << endl; 31 } 32 cout << endl; 33 34 //使用常规new运算符来分配缓冲区 35 chaff *p2 = new chaff[2]; 36 for (int i = 0; i < 2; i++) 37 { 38 cout << "Enter dross: "; 39 char dross[20]; 40 cin.get(dross, 20); 41 strcpy_s(p2[i].dross, dross); 42 cout << "Enter slag: "; 43 cin >> p2[i].slag; 44 cin.get(); 45 } 46 for (int i = 0; i < 2; i++) 47 { 48 cout << "Dross: " << p2[i].dross << endl; 49 cout << "Slag: " << p2[i].slag << endl; 50 } 51 delete[]p2; 52 53 system("pause"); 54 return 0; 55 }
头文件 namesp.h
1 //namesp.h 2 namespace SALES 3 { 4 const int QUARTERS = 4; 5 struct Sales 6 { 7 double sales[QUARTERS]; 8 double average; 9 double max; 10 double min; 11 }; 12 void setSales(Sales &s, const double ar[], int n); 13 14 void setSales(Sales &s); 15 16 void showSales(const Sales &s); 17 }
namesp.cpp
1 #include<iostream> 2 #include"namesp.h" 3 using namespace std; 4 5 namespace SALES 6 { 7 //将4个或n个对象从数组ar中复制到s的sales成员，并计算和存储输入对象的平均值、最大值和最小值 8 //sales的其余元素(如果有的话)设置为0 9 void setSales(Sales &s, const double ar[], int n) 10 { 11 double total = 0; 12 for (int i = 0; i < QUARTERS; i++) 13 { 14 if (i >= n) 15 s.sales[i] = 0; 16 else 17 s.sales[i] = ar[i]; 18 if (i == 0) 19 { 20 s.max = s.sales[i]; 21 s.min = s.sales[i]; 22 } 23 else 24 { 25 if (s.sales[i] > s.max) 26 s.max = s.sales[i]; 27 if (s.sales[i] < s.min) 28 s.min = s.sales[i]; 29 } 30 total += s.sales[i]; 31 } 32 s.average = total / QUARTERS; 33 } 34 35 //以交互方式收集4个季度的销售额，将其存储在s的销售成员中，并计算和存储平均值、最大值和最小值 36 void setSales(Sales &s) 37 { 38 double d[QUARTERS]; 39 for (int i = 0; i < QUARTERS; i++) 40 { 41 cout << "Enter the sales:" << endl; 42 cin >> d[i]; 43 } 44 setSales(s, d, QUARTERS); 45 } 46 47 //显示出来 48 void showSales(const Sales &s) 49 { 50 cout << "Sales:" << endl; 51 for (int i = 0; i < QUARTERS; i++) 52 { 53 cout << s.sales[i] << endl; 54 } 55 cout << "Average: " << s.average << endl; 56 cout << "Max: " << s.max << endl; 57 cout << "Min: " << s.min << endl; 58 } 59 }
main.cpp
1 #include<iostream> 2 #include"namesp.h" 3 using namespace std; 4 5 int main() 6 { 7 using SALES::Sales; 8 using SALES::setSales; 9 using SALES::showSales; 10 11 double d[4] = { 111.11, 222.22, 333.33, 444.44 }; 12 Sales s1, s2; 13 setSales(s1, d, 4); 14 showSales(s1); 15 setSales(s2); 16 showSales(s2); 17 18 system("pause"); 19 return 0; 20 }
