## C++ Primer Plus(第6版)习题(第二章)

1..编写一个C++程序，它显示您的姓名和地址。

```#include<iostream>
using namespace std;

int main()
{
cout << "Your name is "<< name
<< endl;

return 0; ```

2.编写一个C++程序，要求用户输入一个以 long 为单位的距离，然后将它转换为码 。

(1 long = 220 码)

```#include<iostream>
using namespace std;

int main()
{
cout << "Please enter a distance in long: ";
double long;
cin >> long;
double yard = long * 220;
cout << long << " long = "<< yard << " yard."<< endl;

return 0;
}```

3.编写一个C++程序，使用3个用户定义的函数(包括main())，并生产下面的输出：

Three blind mice

Three blind mice

See how they run

```#include<iostream>
void str_1();
void str_2(void);
using namespace std;

int main()
{
str_1();
str_1();
str_2();
str_2();

return 0;
}

void str_1()
{
cout << "Three blind mice."<< endl;
}
void str_2(void)
{
cout << "See how they run."<< endl;
}```

4.编写一个程序，让用户输入其年龄，然后显示该年龄包含多少个月，如下：

Enter you age:29

```#include<iostream>
using namespace std;

int main()
{
int age;
cin >> age;
int contains = age * 12;
cout << "Your age is "<< age
<< " You've been through "<< contains
<< " months."<< endl;

return 0;
}```

5.编写程序，其中的main()调用一个用户定义的函数(以摄氏温度为参考，并返回相应的华氏温度)。该程序按下面的格式要求用户输入摄氏温度值，并显示结果：

20 degress Celsius is 68 degress Fahenheit.

```#include<iostream>
double fah(double);
using namespace std;

int main()
{
cout << "Please enter a Celsius value:";
double cel;
cin >> cel;
fah(cel);
cout << cel << " degrees Celsius is "
<< fah(cel) << " degrees Fahrenheit."
<< endl;

return 0;
}

double fah(double n)
{
double fah = n * 1.8 + 32.0;
return fah;
}```

6.编写程序，其main()调用一个用户定义的函数（以光年值为参数，并返回对应天文单位的值）。该程序按下面的格式要求用户输入光年值，并显示结果：

Enter the number of light years:4.2

4.2 light years = 265608 astronmical units.

```#include<iostream>
double astronomical(double);
using namespace std;

int main()
{
cout << "Enter the number of light years:";
double light_year;
cin >> light_year;
astronomical(light_year);
cout << light_year << " light years = "
<< astronomical(light_year)
<< " astronomical units."
<< endl;

return 0;
}

double astronomical(double n)
{
double ast = n * 63240;
return ast;
}```

7.编写程序，要求用户输入小时数和分钟数。在main()函数中，将这两个值传递给一个 void函数，后者以下面格式显示这两个值：

Enter the number of hours: 9
Enter the number of minutes: 28
Time:9:28

```#include<iostream>
void time(double,double);
using namespace std;

int main()
{
cout << "Enter the number of hours: ";
double hour;
cin >> hour;
cout << "Enter the number of minutes: ";
double minute;
cin >> minute;

time(hour,minute);
return 0;
}
void time(double h,double m)
{
cout << "Time: "<< h <<":"<< m << endl;
}```