C++ Primer Plus 第二章练习题答案

C++ primer plus 课后练习题

以下代码均在Linux下ubuntu 18.04测试过

2.7.1

#include 

//using namespace std;

int main()
{
    //cout << "我的姓名是: 凯" << " 地址是: 江苏 南京" << endl;  
    std::cout << "我的姓名是: 凯" << " 地址是: 江苏 南京" << std::endl;
    return 0;
}

//运行结果为:我的姓名是: 凯 地址是: 江苏 南京

2.7.2

#include 

using namespace std;

int main()
{
    long num = 0;
    cout << "Please input your number:";
    cin >> num;
    cout << "转换为码为:" << num * 220 << "码" << endl;
}

// 运行结果如下
// Please input your number:2.5
// 转换为码为:440码

2.7.3

#include 

using namespace std;

void func1();
void func2();
void func3();

int main()
{
    func1();
    func1();
    func2();
    func3();
    return 0;
}

void func1()
{
    cout << "Three blind mice" << endl;
}

void func2()
{
    cout << "See how they run" << endl;
}

void func3()
{
    cout << "See how they run" << endl;
}
//运行结果如下:
// Three blind mice
// Three blind mice
// See how they run
// See how they run

2.7.4

#include 

using namespace std;

int main()
{
    int age = 0;
    cout << "请输入您的年龄:";
    cin >> age;
    cout << "该年龄包含" << age * 12 << "个月" << endl;
    
    return 0;
}

// 运行结果如下:
// 请输入您的年龄:23
// 该年龄包含276个月

2.7.5

#include 

using namespace std;

float func(int num)
{
    return num * 1.8 + 32;
}

int main()
{
    int num = 0;
    cout << "Please enter a Celsius value: ";
    cin >> num;
    float ret = func(num);
    cout << num << " degrees Celsius is " 
    << ret << " degrees Fahrenheit" << endl;
    
    return 0;
}

// 运行结果如下:
// Please enter a Celsius value: 21
// 21 degrees Celsius is 69.8 degrees Fahrenheit

2.7.6

#include 

using namespace std;

float func(float years)
{
    return years * 63240;
}

int main()
{
    float years;
    cout << "Enter the number of light years:";
    cin >> years;
    int ret = func(years);
    cout << years << " light years = " << ret << " astronomical units" << endl;;
    
    return 0;
}

// 运行结果如下:
// Enter the number of light years:4.2
// 4.2 light years = 265608 astronomical units

2.7.7

#include 

using namespace std;

void func(int hours, int minutes)
{
    cout << "Time: " << hours << ":" << minutes << endl; 
}

int main()
{
    int hours, minutes;
    cout << "Enter the number of hours:";
    cin >> hours;
    cout << "Enter the number of minutes:";
    cin >> minutes;
    func(hours, minutes);
    return 0;
}

// 运行结果如下:
// Enter the number of hours:9
// Enter the number of minutes:28
// Time: 9:28