C++primer plus第六版课后编程练习答案2.6

#include <iostream>
using namespace std;

double LightyearsToAstronomicalUnits(double lightyears)
{
return (63240*lightyears);
}

double LightyearsToKm(double lightyears)//double 可以支持15-16位有效数字，float只能支持6位有效数字
{
return (10000000000000*lightyears);
}

int main()
{
double lightyears;
cout<<"Enter a number of light years:";
cin>>lightyears;
cout<<lightyears<<" light years = "<<LightyearstoAstronomicalUnits(lightyears)
<<" astronomical units = "<<LightyearstoKm(lightyears)<<" Km.\n";
return 0;
}