我这个为什么编译不通过呀（第二个图片的就编译通过）

Question

#include<iostream>
using namespace std;

class Cuboid
{
	private:
		double lengit;
		double width;
		double height;
		double area;
		double volume;
	public:
		void set_value(double x,double y,double z);
		void count_area();
		void count_volume();
		void show();
};

inline void set_value(double x,double y,double z)
{
	lengit=x;
	width=y;
	height=z;
	
};

inline void count_area()
{
	area=(lengit*width+width*height+lengit*height)*2;
};

inline void count_volume()
{
	volume=width*height*lengit;
};

inline void show()
{
	cout<<"area="<<area<<","<<"volume="<<volume<<endl;
};

int main()
{
    Cuboid cc;
        float a,b,c;
        cin>>a>>b>>c;
    cc.set_value(a,b,c);
    cc.count_area();
    cc.count_volume();
    cc.show();
    return 0;
}

 

 

Answer 1

在类外定义类函数需要：类名：：函数名(参数)，这种方式