1.编写一个C++程序,如下述输出示例所示的那样请求并显示消息:
What is your first name? Betty Sue
What is your last name? Yewe
What letter grage do you deserve? B
What is your age? 22
Name: Yewe, Betty Sue
Grade : C
Age : 22
注意,该程序应该接受的名字包含多个单词。另外,程序将向下调整成绩,即向上调一个字母。
假设用户请求A、B或C,所以不必担心D和F之间的空挡。
const int size = 20; char first_name[size], last_name[size]; char grade; int age; cout << "What is your first name?"; cin.getline(first_name,size); cout << "What is your last name?"; cin.getline(last_name, size); cout << "What letter grade do you deserve?"; cin >> grade; cout << "What is your age?"; cin >> age; cout << "Name: " << last_name << ", " << first_name << endl; cout << "Grade: " << (char)(grade + 1) << endl; cout << "Age: " << age;
2.修改程序清单4.4,使用C++string类而不是char数组。
//程序清单4.4 const int ArSize = 20; char name[ArSize]; char dessert[ArSize]; cout << "Enter your name: " << endl; cin.getline(name, ArSize); cout << "Enter your favourite dessert: " << endl; cin.getline(dessert, ArSize); cout << "I have some delicious " << dessert; cout << " for you, " << name << ".\n";
修改后
string name; string dessert; cout << "Enter your name: " << endl; getline(cin, name); cout << "Enter your favourite dessert: " << endl; getline(cin, dessert); cout << "I have some delicious " << dessert; cout << " for you, " << name << ".\n";
3.编写一个程序,它要求用户首先输入其名,然后输入其姓,然后程序使用一个逗号和空格将姓和名组合起来,并存储和显示组合结果。请使用char数组和头文件cstring中的函数。下面是该程序运行时的情形:
Enter your first name : Flip
Enter your last name : Fleming
Here’s the information in a single string: Fleming, Flip
const int SIZE = 20; char first_name[SIZE]; char last_name[SIZE]; char full_name[2*SIZE]; cout << "Enter your first name: "; cin.getline(first_name, SIZE); cout << "Enter your last name: "; cin.getline(last_name, SIZE); strcpy(full_name, last_name); strcat(full_name, ", "); strcat(full_name, first_name); cout << "Here's the information in a single string: " << full_name << endl;
4.编写一个程序,它要求用户首先输入其名,再输入其姓,然后程序使用一个逗号和空格将姓和名组合起来,并存储和显示组合结果。请使用string对象和头文件string中的函数。下面是该程序运行时的情形:
Enter your first name : Flip
Enter your last name : Fleming
Here’s the information in a single string: Fleming, Flip
string first_name, last_name, full_name; cout << "Enter your first name: "; getline(cin, first_name); cout << "Enter your last name: "; getline(cin, last_name); full_name = last_name + ", " + first_name; cout << "Here's the information in a single string: " << full_name << endl;
5.结构CandyBar包含3个成员。第一个成员存储了糖块的品牌;第二个成员存储糖块的重量(可以有小数);第三个成员存储了糖块的卡路里含量(整数)。请编写一个程序,声明这个结构,创建一个名为snack的CandyBar变量,并将其成员分别初始化为"Mocha Munch"、2.3和350。初始化应在声明snack时进行。最后程序显示snack变量的内容。
struct CandyBar { char brand[20]; float weight; unsigned int calorie; }; int main() { using std::cin; using std::cout; using std::endl; CandyBar snack = { "Mocha Munch", 2.3, 350}; cout << "Brand: " << snack.brand << ", Weight: " << snack.weight << ", Calorie: " << snack.calorie << endl; return 0; }
6.结构体CandyBar包含3个成员,如编程练习5所示。请编写一个程序,创建一个包含3个元素的CandyBar数组,并将他们初始化为所选择的值,然后显示每个结构的内容。
CandyBar snack[3] = {{ "Mocha Munch", 2.3, 350 }, {"Name2", 3.2, 500}, {"Name3", 4.3, 600} }; cout << "1st Brand: " << snack[0].brand << ", "; cout << "1st Weight: " << snack[0].weight << ", "; cout << "1st Calorie: " << snack[0].calorie << endl; cout << "---------------------------" << endl; cout << "2nd Brand: " << snack[1].brand << ", "; cout << "2nd Weight: " << snack[1].weight << ", "; cout << "2nd Calorie: " << snack[1].calorie << endl; cout << "---------------------------" << endl; cout << "3th Brand: " << snack[2].brand << ", "; cout << "3th Weight: " << snack[2].weight << ", "; cout << "3th Calorie: " << snack[2].calorie << endl;
7.William Wingate从事比萨饼分析服务。对于每个比萨饼,他都需要记录下列信息:
比萨饼公司的名称,可以有多个单词组成。
比萨饼的直径。
比萨饼的重量。
请设计一个能够存储这些信息的结构体,并编写一个使用这种结构变量的程序。程序将请求用户输入上述信息,然后显示这些信息。请使用cin(或它的方法)和cout。
struct Pizza { char company[20]; float diameter; float weight; }; int main() { using std::cin; using std::cout; using std::endl; Pizza dinner; cout << "Please enter the Pizza's company: "; cin.getline(dinner.company, 20); cout << "Please enter the size of pizza in inches: "; cin >> dinner.diameter; cout << "Please enter the weight of pizza in pounds: "; cin >> dinner.weight; cout << "Pizza company:" << dinner.company << ", diameter in inches:" << dinner.diameter << ", weight in pounds:" << dinner.weight << ".\n"; return 0; }
8.完成编程练习7,但使用new来为结构分配内存,而不是声明一个结构变量。另外,让程序在请求输入比萨饼公司之前输入比萨饼的直径。
Pizza *pt = new Pizza; cout << "Please enter the Pizza's company: "; cin.getline(pt->company, 20); cout << "Please enter the size of pizza in inches: "; cin >> pt->diameter; cout << "Please enter the weight of pizza in pounds: "; cin >> pt->weight; cout << "Pizza company:" << pt->company << ", diameter in inches:" << pt->diameter << ", weight in pounds:" << pt->weight << ".\n"; delete pt;
9.完成编程练习6,但使用new来动态分配数组,而不是声明一个包含3个元素的CandyBar数组。
CandyBar* pt = new CandyBar[3];// = { "Mocha Munch", 2.3, 350 }; strcpy(pt[0].brand, "Mocha Munch"); pt[0].weight = 2.3; pt[0].calorie = 350; strcpy(pt[1].brand, "Name2"); pt[1].weight = 3.2; pt[1].calorie = 500; strcpy(pt[2].brand, "Name3"); pt[2].weight = 4.3; pt[2].calorie = 600; cout << "1st Brand: " << pt->brand << ", "; cout << "1st Weight: " << pt->weight << ", "; cout << "1st Calorie: " << pt->calorie << endl; cout << "---------------------------" << endl; cout << "2nd Brand: " << (pt + 1)->brand << ", "; cout << "2nd Weight: " << (pt + 1)->weight << ", "; cout << "2nd Calorie: " << (pt + 1)->calorie << endl; cout << "---------------------------" << endl; cout << "3th Brand: " << (pt + 2)->brand << ", "; cout << "3th Weight: " << (pt + 2)->weight << ", "; cout << "3th Calorie: " << (pt + 2)->calorie << endl; delete[] pt;
10.编写一个程序,让用户输入三次40码跑的成绩(如果您愿意,也可让用户输入40米跑的成绩),并显示次数和 平均成绩。请使用一个array对象来存储数据(如果编译器不支持array类,请使用数组。)
#include <iostream> #include <array> int main() { using std::cin; using std::cout; using std::endl; using std::array; array<float, 3> record_list; float average; cout << "Please enter three records of 40 meters: " << endl; cout << "First record: "; cin >> record_list[0]; cout << "Second record: "; cin >> record_list[1]; cout << "Third record: "; cin >> record_list[2]; cout << "1st: " << record_list[0] << "; " << "2nd: " << record_list[1] << "; " << "3rd: " << record_list[2] << endl; average = (record_list[0] + record_list[1] + record_list[2]) / 3; cout << "The average of records is: " << average << ".\n"; return 0; }