项目1.4在构造函数中使用参数初始化表对数据成员初始化

<pre name="code" class="cpp">#include <iostream>
#include <cmath>
using namespace std;
class  Triangle
{
public:
Triangle(double x,double y,double z):a(x),b(y),c(z){};
double perimeter();
double area();
void showMassage();
private:
double a,b,c;
};

double Triangle::perimeter()
{
return a+b+c;
}
double Triangle::area()
{
double s = (a + b + c) / 2;
return sqrt(s * (s - a) * (s - b) * (s - c));
}
void Triangle::showMassage()
{
cout<<"三角形的三边长分别是："<<a<<" "<<b<<" "<<c<<endl;
cout<<"三角形的周长是："<<perimeter()<<", 面积是："<<area()<<endl;
}
int main()
{
Triangle Tri(7,8,9);
Tri.showMassage();
return 0;
}