帮我看下这个程序,谢谢

#include using namespace std;class Dog{ public: Dog(int NewA,int NewW); void Eat(int NewA,int NewW); void Walk(); ~Dog(){}; private: int Age,Weight;};Dog::Dog(int NewA,int NewW){ Age=NewA; Weight=NewW;}void Dog::Eat(int NewA,int NewW){ cout<<"Dog can eat!"<<endl; cout<<"Age:"<<Age<<"years old"<<endl; cout<<"Weight:"<<Weight<<"kg"<<endl;}void Dog::Walk(){ cout<<"Dog can walk!"<<endl;}int main(){ Dog dog; dog.Eat(3,20); dog.Walk(); return 0;}C:\Users\wangyun\Desktop\temp\work.cpp(30) : error C2512: 'Dog' : no appropriate default constructor available不懂哪里出错了

#include <iostream>
using namespace std;
class Dog{
public:
Dog(){}
Dog(int NewA,int NewW);
void Eat(int NewA,int NewW);
void Walk();
~Dog(){};
private:
int Age,Weight;};
Dog::Dog(int NewA,int NewW)
{ Age=NewA; Weight=NewW;}
void Dog::Eat(int NewA,int NewW)
{ cout<<"Dog can eat!"<<endl;
cout<<"Age:"<<Age<<"years old"<<endl;
cout<<"Weight:"<<Weight<<"kg"<<endl;}
void Dog::Walk(){ cout<<"Dog can walk!"<<endl;}
int main(){ Dog dog; dog.Eat(3,20); dog.Walk(); return 0;}

你建立了构造函数是有参数的,可你创建类对象时没有给出参数

大师，我只学过C哦！这个高深的看不懂。。。