C++ Primer Plus（第六版）中文版编程练习答案
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45 C++ Primer Plus（第六版）第四章 编程练习答案
1
#include<iostream>
#include<string>
#include<vector>
#include<array>
using namespace std;
int main()
{
char firstname[20];
char lastname[20];
char grade;
//enum grade { A,B,C,D,F };
int age;
cout << "What's your first name? ";
cin.getline(firstname, 19);
cout << "What's your last name? ";
cin.getline(lastname, 19);
cout << "What letter grade do you deserve? ";
cin >> grade;
cout << "What's your age? ";
cin >> age;
cout << "Name: " << firstname << ", " << lastname << endl;
cout << "Grade: " << char(grade + 1) << endl;//向下调整成绩，即上调一个字母，grade+1
cout << "Age: " << age << endl;
system("pause");
return 0;
}
2
// instr2.cpp -- reading more than one word with getline
#include <iostream>
#include<string>
int main()
{
using namespace std;
const int ArSize = 20;
//char name[ArSize];
//char dessert[ArSize];
//cout << "Enter your name:\n";//abcdefghijklmnopqrs
//cin.getline(name, ArSize); // reads through newline
//cout << "Enter your favorite dessert:\n";
//cin.getline(dessert, ArSize);
//cout << "I have some delicious " << dessert;
//cout << " for you, " << name << ".\n";
// cin.get();
string name;
string dessert;
cout << "Enter your name:\n";
getline(cin, name);//将一行输入读取到string对象中。
//istream有类中，有处理double、int等基本数据类型的类方法，没有处理string对象的类方法。
char arr[ArSize];
cout << "Enter arr:";
cin.getline(arr, 20);
//cin >> name;//只能读取第一个单词，后续单词自动给到下一个读取
cout << "Enter your favorite dessert:\n";
getline(cin, dessert);//将一行输入读取到string对象中
//cin >> dessert;//只能读第一个单词，后续单词自动给到下一个读取
cout << "I have some delicious " << dessert;
cout << " for you, " << name << ".\n";
cout << "arr = " << arr << endl;
system("pause");
return 0;
}
3
// instr2.cpp -- reading more than one word with getline
#include <iostream>
#include<cstring>
int main()
{
using namespace std;
char firstname[20];
char lastname[20];
char name[40];
cout << "Enter your first name : ";
cin.getline(firstname, 19);
cout << "Enter your last name : ";
cin.getline(lastname, 19);
strcpy_s(name, lastname);
strcat_s(name, ", ");
strcat_s(name, firstname);
cout << "Here's the information in a single string : " << name << endl;
system("pause");
return 0;
}
4
// instr2.cpp -- reading more than one word with getline
#include <iostream>
#include<string>
using namespace std;
int main()
{
//char firstname[20];
//char lastname[20];
//char name[40];
//cout << "Enter your first name : ";
//cin.getline(firstname, 19);
//cout << "Enter your last name : ";
//cin.getline(lastname, 19);
//strcpy_s(name, lastname);
//strcat_s(name, ", ");
//strcat_s(name, firstname);
//cout << "Here's the information in a single string : " << name << endl;
string firstname;
string lastname;
string name;
cout << "Enter your first name : ";
getline(cin, firstname);
cout << "Enter your last name : ";
getline(cin, lastname);
/*name = lastname;
name += ", ";
name += firstname;*/
name = lastname + ", " + firstname;
cout << "Here's the information in a single string : " << name << endl;
system("pause");
return 0;
}
5
#include<iostream>
#include<string>
using namespace std;
struct CandyBar
{
string name;
float weight;
int calorie;
};
int main()
{
/*CandyBar snack;
snack.name = "Mocha Munch";
snack.weight = 2.3;
snack.calorie = 350;*/
CandyBar snack{ "Mocha Munch",2.3,350 };
cout << "snack's name: " << snack.name << endl << "snack's weight: " << snack.weight << endl << "snack's calorie: " << snack.calorie << endl;
system("pause");
return 0;
}
6
#include<iostream>
#include<string>
using namespace std;
struct CandyBar
{
string name;
float weight;
int calorie;
};
int main()
{
/*CandyBar snack;
snack.name = "Mocha Munch";
snack.weight = 2.3;
snack.calorie = 350;*/
CandyBar snack{ "Mocha Munch",2.3,350 };
cout << "snack's name: " << snack.name << endl << "snack's weight: " << snack.weight << endl << "snack's calorie: " << snack.calorie << endl;
/*CandyBar candy[3];
candy[0] = { "Mocha Munch",2.3,350 };
candy[1] = { "aer beisi",3.3,650 };
candy[2] = { "wo wo",6.3,50 };*/
CandyBar candy[3]{ { "Mocha Munch",2.3,350 },
{ "aer beisi",3.3,650 },
{ "wo wo",6.3,50 } };
cout << "candy[0]: " << endl;
cout << "candy[0].name: " << candy[0].name << endl << "candy[0].weight: " << candy[0].weight << endl << "candy[0].calorie: " << candy[0].calorie << endl;
cout << "candy[1]: " << endl;
cout << "candy[1].name: " << candy[1].name << endl << "candy[1].weight: " << candy[1].weight << endl << "candy[1].calorie: " << candy[1].calorie << endl;
cout << "candy[2]: " << endl;
cout << "candy[2].name: " << candy[2].name << endl << "candy[2].weight: " << candy[2].weight << endl << "candy[2].calorie: " << candy[2].calorie << endl;
system("pause");
return 0;
}
7
#include<iostream>
#include<string>
using namespace std;
struct Pizza
{
string name;
float diameter;
float weight;
};
int main()
{
Pizza p1;
cout << "Enter Pizza's name: ";
getline(cin, p1.name);
cout << "Enter Pizza's diameter: ";
cin >> p1.diameter;
cout << "Enter Pizza's weight: ";
cin >> p1.weight;
cout << "Pizza's name: " << p1.name << endl << "Pizza's diameter: " << p1.diameter << endl << "Pizza's weight: " << p1.weight << endl;
system("pause");
return 0;
}
8
#include<iostream>
#include<string>
using namespace std;
struct Pizza
{
string name;
float diameter;
float weight;
};
int main()
{
//Pizza* p = new Pizza;
//cout << "Enter Pizza's name: ";
//getline(cin, p->name);
getline(cin, (*p).name);
//cout << "Enter Pizza's diameter: ";
//cin >> p->diameter;
cin >> (*p).diameter;
//cout << "Enter Pizza's weight: ";
//cin >> p->weight;
cin >> (*p).weight;
//cout << "Pizza's name: " << (*p).name << endl << "Pizza's diameter: " << (*p).diameter << endl << "Pizza's weight: " << (*p).weight << endl;
//delete p;
Pizza* p = new Pizza;
cout << "Enter Pizza's diameter: ";
cin >> p->diameter;
//cin >> (*p).diameter;
cin.get();
cout << "Enter Pizza's name: ";
getline(cin, p->name);
//getline(cin, (*p).name);
cout << "Enter Pizza's weight: ";
cin >> p->weight;
//cin >> (*p).weight;
cout << "Pizza's name: " << (*p).name << endl << "Pizza's diameter: " << (*p).diameter << endl << "Pizza's weight: " << (*p).weight << endl;
delete p;
system("pause");
return 0;
}
9
#include<iostream>
#include<string>
using namespace std;
struct CandyBar
{
string name;
float weight;
int calorie;
};
int main()
{
///*CandyBar snack;
//snack.name = "Mocha Munch";
//snack.weight = 2.3;
//snack.calorie = 350;*/
//CandyBar snack{ "Mocha Munch",2.3,350 };
//cout << "snack's name: " << snack.name << endl << "snack's weight: " << snack.weight << endl << "snack's calorie: " << snack.calorie << endl;
///*CandyBar candy[3];
//candy[0] = { "Mocha Munch",2.3,350 };
//candy[1] = { "aer beisi",3.3,650 };
//candy[2] = { "wo wo",6.3,50 };*/
//CandyBar candy[3]{ { "Mocha Munch",2.3,350 },
// { "aer beisi",3.3,650 },
// { "wo wo",6.3,50 } };
//cout << "candy[0]: " << endl;
//cout << "candy[0].name: " << candy[0].name << endl << "candy[0].weight: " << candy[0].weight << endl << "candy[0].calorie: " << candy[0].calorie << endl;
//cout << "candy[1]: " << endl;
//cout << "candy[1].name: " << candy[1].name << endl << "candy[1].weight: " << candy[1].weight << endl << "candy[1].calorie: " << candy[1].calorie << endl;
//cout << "candy[2]: " << endl;
//cout << "candy[2].name: " << candy[2].name << endl << "candy[2].weight: " << candy[2].weight << endl << "candy[2].calorie: " << candy[2].calorie << endl;
CandyBar* p = new CandyBar[3];
p[0] = { "Mocha Munch",2.3,350 };
p[1] = { "aer beisi",3.3,650 };
p[2] = { "wo wo",6.3,50 };
cout << "p[0]: " << endl;
cout << "p[0].name: " << p[0].name << endl << "p[0].weight: " << p[0].weight << endl << "p[0].calorie: " << p[0].calorie << endl;
cout << "p[1]: " << endl;
cout << "p[1].name: " << p[1].name << endl << "p[1].weight: " << p[1].weight << endl << "p[1].calorie: " << p[1].calorie << endl;
cout << "p[2]: " << endl;
cout << "p[2].name: " << p[2].name << endl << "p[2].weight: " << p[2].weight << endl << "p[2].calorie: " << p[2].calorie << endl;
delete[]p;
system("pause");
return 0;
}
10
#include<iostream>
#include<string>
using namespace std;
#include<array>
const int times = 3;
int main()
{
array<float, times> arr;
float result = 0;
/*cout << "Enter the result of the 50-meter run: ";
cin >> arr[0];
cout << "Enter the result of the 50-meter run: ";
cin >> arr[1];
cout << "Enter the result of the 50-meter run: ";
cin >> arr[2];*/
for (int i = 0; i < times; i++)
{
cout<< "Enter the result of the 50-meter run: ";
cin >> arr[i];
result += arr[i];
}
float average = result / times;
cout << "Times: " << times << endl;
cout << "Average result: " << average << endl;
cout << "Total result: " << result << endl;
system("pause");
return 0;
}
标签：snack,cout,weight,int,C++,第六版,Plus,include,name 来源： https://blog.csdn.net/yuandenixin/article/details/117047623