CPP_Basic_Code_P2.1-PP2.7.7

//  The Notes Created by Z-Tech on 2017/2/17.
//  All Codes Boot on 《C++ Primer Plus》V6.0
//  OS：MacOS 10.12.4
//  Translater：clang/llvm8.0.0 &g++4.2.1
//  Editer：iTerm 2&Sublime text 3
//  IDE: Xcode8.2.1&Clion2017.1

//P2.1
#include <iostream>//Hello，C++
int main()
{
    using namespace std;
    cout <<"Come up and C++ me some time.";
    cout <<endl;
    cout <<"You won't regret it"<<endl;
    return 0;
}

//P2.2
#include <iostream>
int main()
{
    using namespace std;
    int carrots;
    carrots=25;
    cout<<"I Have ";
    cout<<carrots;
    cout<<" carrots.";//注意前后空格
    cout<<endl;
    carrots=carrots-1;
    cout<<"Crunch,crunch,Now I have "<<carrots<<" carrots."<<endl;
    return 0;
}

//P2.3
#include <iostream>
int main()
{
    using namespace std;
    int carrots;
    cout<<"How many Carrots do you have?"<<endl;
    cin>>carrots;
    cout<<"Here are two more. ";
    carrots=carrots+2;
    cout<<"Now you have "<<carrots<<" carrots."<<endl;//输出流
    return 0;
}

//P2.4
#include <iostream>
#include <cmath>//是C中math.h的升级
int main()
{
    using namespace std;
    double area;
    cout<<"Enter the floor area,in square feet,of your home:";
    cin>>area;
    double side=sqrt(area);//开方计算
    cout<<"That's the equvalent of a square  "<<side
        <<" feet to the side."<<endl;
    cout<<"How Fascinating"<<endl;
    return 0;
}

//P2.5
#include <iostream>
void simon(int)//函数声明
int main()
{
    using namespace std;
    simon(3);
    cout<<"Pick an integer: ";
    int count;
    cin>>count;
    simon(count);
    cout<<"Done"<<endl;
    return 0;
}
void simon(int n)//打印函数，无返回值。
{
    using namespace std;
    cout<<"Simon says touch your toes "<<n<<" times"<<endl;
}

//P2.6
#include <iostream>
int stonetolb(int);
int main()
{
    using namespace std;
    int stone;
    cout<<"Enter the weight in stone:";
    cin>>stone;
    int pounds=stonetolb(stone);
    cout<<stone<<" stone= ";
    cout<<pounds<<" pounds."<<endl;
    return 0;
}
int stonetolb(int sts)
{
    return 14*sts;//1英石=14磅，使用表达式避免创建新变量
}

//PP2.7.2
#include <iostream>
int main()
{
    using  namespace std;
    cout<<"Please input a distance:";
    double xLong;
    cin>>xLong;
    double  Ma=220*xLong;
    cout<<xLong<<"long = "<<Ma<<"Ma";
    return 0;
}

//PP2.7.3
#include <iostream>
void z_tech1();
void z_tech2();
int main()
{
    using namespace std;
    z_tech1();//无参数无返回值
    z_tech1();
    z_tech2();
    z_tech2();
    return 0;
}
void z_tech1()
{
    using namespace std;
    cout<<"Three blind mice "<<endl;
}
void z_tech2()
{
    using namespace std;
    cout<<"See how they run "<<endl;
}

//PP2.7.4
#include<iostream>
int main()
{
    using namespace std;
    cout<<"Please enter your age(years):"<<endl;
    int Year;
    cin>>Year;
    cout<<Year<<" years is about "<<12*Year<<" months.";
    return 0;
}

//PP2.7.5
#include <iostream>
double Fahrenheit(double);
int main()
{
    using namespace std;
    cout<<"Please enter a celsius value: "<<endl;
    double Celsius;
    cin>>Celsius;
    cout<<Celsius<<" degrees Celsius is "<<Fahrenheit(Celsius)<<" degrees Fahrenheit.";
    return 0;
}
double Fahrenheit(double n)
{
    n=1.8*n+32.0;
    return n;
}

//PP2.7.6
#include <iostream>
double astronomical_units(double);
int main()
{
    using namespace std;
    cout<<"Please enter the number of light year: "<<endl;
    double Lightyear;
    cin>>Lightyear;
    double astr_units=astronomical_units(Lightyear);
    cout<<Lightyear<<" light year = "<<astr_units<<" astronomical units.";
    return 0;
}
double astronomical_units(double x)
{
    x=63240*x;
    return x;
}

//PP2.7.7
#include <iostream>
void time(int,int);//多参数申明
int main()
{
    using namespace std;
    cout<<"Please enter the number of hours: ";
    int hours;
    cin>>hours;
    cout<<"Please enter the number of minutes: ";
    int minutes;
    cin>>minutes;
    time(hours,minutes);
    return 0;
}
void time(int a,int b)//多参数函数实体
{
    using namespace std;
    cout<<"Time: "<<a<<":"<<b;
}