Question

C++问题,为什么没有错误,运行结果却不对

//4-5 类与对象
#include <iostream.h>
class Box
{
public:
void Init(double L,double W,double H);
double Vol();
private:
double length,width,heighth;
};
void Box::Init(double L,double W,double H)
{
length=L;
width=W;
heighth=H;
}

double Box::Vol()
{
return length*width*heighth;
}

void main()
{
Box cube;
double a,b,c;
cout<<"请输如立方体的长宽高"<<endl;
cin>>a,b,c;
cube.Init(a,b,c);
cout<<"The vol of the cube is"<<cube.Vol()<<endl;
}

Answer 1

把MAIN函数改成下面就对了：
void main()
{
Box cube;
double a=0,b=0,c=0; //注意这里最好初始化
cout<<"请输如立方体的长宽高"<<endl;
cin>>a>>b>>c; //注意这里的写法，原文是cin>>a,b,c;不对！
cube.Init(a,b,c);
cout<<"The vol of the cube is "<<cube.Vol()<<endl;
}

Answer 2

#include <iostream.h>
class Box
{
public:
void Init(double L,double W,double H);
double Vol();
private:
double length,width,heighth;
};
void Box::Init(double L,double W,double H)
{
length=L;
width=W;
heighth=H;
}

double Box::Vol()
{
return length*width*heighth;
}

void main()
{
Box cube;
double a,b,c;
cout<<"请输如立方体的长宽高"<<endl;
cin>>a>>b>>c;//问题在这，后面两个变量没输上值
cube.Init(a,b,c);
cout<<"The vol of the cube is"<<cube.Vol()<<endl;
}