C++ Primer Plus（第6版）第2章 开始学习C++

复习题
1 函数
2 用iostream头文件的内容替换源代码中的#include语句
3 使std名称空间中的内容全部直接可用
4 std::cout<<"hello world"<<endl;
5 int cheeses;
6 cheeses=32;
7 std::cin>>cheeses;
8 std::cout<<"We have "<<cheeses<<"varieties of cheese,";
9 参数数量和类型，返回值的类型
10 main函数可以省略 返回值为void的函数可以不使用
11 没指定名称空间
std::cout
using namespace std
using std::cout

编程练习
1

#include<iostream>
int main(void)
{
    std::cout<<"姓名"<<std::endl<<"地址"<<std::endl;
    return 0;
}

2

#include<iostream>
int main(void)
{
    using namespace std;
    int i;
    cout<<"input a distance in long\n";
    cin>>i;
    cout<<"the distance is "<<i*220<<"foot"<<endl;
    return 0;
}

3

#include<iostream>
void blind(void);
void see(void);
int main(void)
{
    blind();
    blind();
    see();
    see();
    return 0;
}
void blind(void)
{
    using namespace std;
    cout<<"Three blind mice"<<endl;
}
void see(void)
{
    using namespace std;
    cout<<"See how they run"<<endl;
}

4

#include<iostream>
int main(void)
{
    using namespace std;
    int age;
    cout<<"Enter your age: ";
    cin>>age;
    cout<<"it has "<<age*12<<"months"<<endl;
    return 0;
}

5

#include<iostream>
double reverse(double);
int main(void)
{
    using namespace std;
    double c;
    cout<<"please enter a Celsius value: ";
    cin>>c;
    cout<<c<<" degree Celsius is "<<reverse(c)<<" degree Fahrenheit."<<endl;
    return 0;
}
double reverse(double i)
{
    return i*1.8+32;
}

6

#include<iostream>
double reverse(double);
int main(void)
{
    using namespace std;
    double l;
    cout<<"Enter the number of light years: ";
    cin>>l;
    cout<<l<<" light years = "<<reverse(l)<<" astronomical units."<<endl;
    return 0;
}
double reverse(double i)
{
    return i*63240;
}

7

#include<iostream>
void showtime(int,int);
int main(void)
{
    using namespace std;
    int h,m;
    cout<<"Enter the number of hours: ";
    cin>>h;
    cout<<"Enter the number of minutes: ";
    cin>>m;
    showtime(h,m);
    return 0;
}
void showtime(int i,int j)
{
    std::cout<<"Time: "<<i<<":"<<j<<std::endl;
}