c++ primer plus 第四章 课后题答案

#include<iostream>
#include<string>

using namespace std;

int main()
{
    string first_name;
    string last_name;
    char grade;
    int age;

    cout << "What is your first name? ";
    getline(cin,first_name);
    cout << endl << "What is your last name? ";
    getline(cin,last_name);
    cout << endl << "What letter grade do you deserve? ";
    cin >> grade;
    cout << endl << "What is your age? ";
    cin >> age;
    
    cout << "Name: " << last_name << ", " << first_name << endl;
    cout << "Grade: " << char(grade + 1) << endl;
    cout << "Age: " << age << endl;
    cin.get();
    cin.get();
    return 0;
}

 

#include <iostream>
#include<string>

int main()
{
    using namespace std;

    string name;
    string dessert;

    cout << "Enter your name:
";
    getline(cin,name);
    cout << "Enter your favorite dessert:
";
    getline(cin,dessert);
    cout << "I have some delicious " << dessert;
    cout << " for you, " << name << ".
";
    cin.get();
    return 0;
}

 

#include<iostream>
#include<cstring>

using namespace std;

int main()
{
    char first_name[20];
    char last_name[20];
    char name[41];

    cout << "Enter your first name: ";
    cin >> first_name;
    cout << endl << "Enter your last name: ";
    cin >> last_name;

    strcpy_s(name, last_name);
    strcat_s(name, ",");
    strcat_s(name, first_name);
    cout << endl << "Here’s the information in a single string: " << name;
    
    //cout << endl << "Here’s the information in a single string: " << last_name << " , " << first_name;

    cin.get();
    cin.get();
    return 0;
}

 

#include<iostream>
#include<string>

using namespace std;

int main()
{
    string first_name;
    string last_name;
    string name;

    cout << "Enter your first name: ";
    getline(cin,first_name);
    cout << "Enter your last name: ";
    getline(cin,last_name);

    name = last_name + "," + first_name;
    cout << "Here's the information in a single string: " << name << endl;
    cin.get();
    //system("pause");
    return 0;
}

 

#include<iostream>
using namespace std;

struct CandyBar
{
    char bard[20];
    double weight;
    int calories;
};

int main()
{
    CandyBar snack =
    {
        "Mocha Munch",
        2.3,
        350
    };

    cout << "The bard of this candy is: " << snack.bard << endl;
    cout << "The weight of this candy is: " << snack.weight << endl;
    cout << "The calories of this candy is: " << snack.calories << endl;

    cin.get();
    return 0;
}

 

#include<iostream>
using namespace std;

struct Candy {
    char name[20];
    double weight;
    int calories;
};

int main() {
    //Candy snack[3];
    //snack[0] = { "Mocha Munch1", 2.3, 350 };
    //snack[1] = { "Mocha Munch2", 2.5, 360 };
    //snack[2] = { "Mocha Munch3", 2.7, 390 };
    Candy snack[3] = { { "Mocha Munch1", 2.3, 350 } ,
                       { "Mocha Munch2", 2.5, 360 } ,
                       { "Mocha Munch3", 2.7, 390 } };
    cout << snack[0].name << "'s weight is " << snack[0].weight <<
        ", and it includes " << snack[0].calories << " calories.
";
    cout << snack[1].name << "'s weight is " << snack[1].weight <<
        ", and it includes " << snack[1].calories << " calories.
";
    cout << snack[2].name << "'s weight is " << snack[2].weight <<
        ", and it includes " << snack[2].calories << " calories.
";

    system("pause");
    return 0;
}

 

#include<iostream>
using namespace std;

struct Pizza
{
    char name[20];
    double diameter;
    double weight;
};

int main()
{
    Pizza x;
    cout << "Please enter the name of this pizza: ";
    cin >> x.name;
    cout << "Please enter the diameter of this pizza: ";
    cin >> x.diameter;
    cout << "Please enter the weight of this pizza: ";
    cin >> x.weight;

    cout << "The name of this pizza is " << x.name << endl;
    cout << "The diameter of this pizza is " << x.diameter << endl;
    cout << "The weight of this pizza is " << x.weight << endl;

    system("pause");
    return 0;
}

 

#include<iostream>
using namespace std;

struct Pizza {
    char name[20];
    double diameter;
    double weight;
};

int main() {
    Pizza *pizza = new Pizza;
    cout << "Please enter the name of this pizza: ";
    cin >> pizza->name;
    cout << "Please enter the diameter of this pizza: ";
    cin >> pizza->diameter;
    cout << "Please enter the weight of this pizza: ";
    cin >> pizza->weight;

    cout << "The name of this pizza is " << pizza->name << endl;
    cout << "The diameter of this pizza is " << pizza->diameter << endl;
    cout << "The weight of this pizza is " << pizza->weight << endl;

    delete pizza;

    system("pause");
    return 0;
}

 

#include<iostream>
using namespace std;

struct Candy {
    char name[20];
    double weight;
    int calories;
};

int main()
{
    Candy *snack = new Candy[3];
    snack[0] = { "Mocha Munch1", 2.3, 350 };
    snack[1] = { "Mocha Munch2", 2.5, 360 };
    snack[2] = { "Mocha Munch3", 2.7, 390 };

    cout << snack[0].name << "'s weight is " << snack[0].weight <<
        ", and it includes " << snack[0].calories << " calories.
";
    cout << snack[1].name << "'s weight is " << snack[1].weight <<
        ", and it includes " << snack[1].calories << " calories.
";
    cout << snack[2].name << "'s weight is " << snack[2].weight <<
        ", and it includes " << snack[2].calories << " calories.
";

    delete [] snack;

    system("pause");
    return 0;
}

#include<iostream>
#include<array>

using namespace std;
const int Times = 3;

int main()
{
    array<double, Times> grade;
    int i;
    double avg_grade=0.0;

    cout << "Please enter your grade: " << endl;
    
    for (i = 0; i <= 2; i++)
    {
        cout << endl << ("%d", i+1) << " time: ";
        cin >> grade[i];
        avg_grade += grade[i];
    }

    avg_grade = avg_grade / Times;
    cout << endl << "The grade of average is: " << avg_grade << endl;

    system("pause");
    return 0;
}