有分加啊!,这个程序错误何在???????

[benny106]

#include<iostream.h>
class rational
{
public:
void ration(int z1,int z2,int m1,int m2)
{
n1=z1;n2=z2;n3=m1;n4=m2;
}
rational()
{
cout<<"输入一个数的分子。\n";
cin>>z1;
cout<<"输入一个数的分母。\n";
cin>>m1;

}
void start()
{
int choice;
cout<<"请输入+,-,*,/\n1.+\n2.-\n3.*\n4./\n";
cin>>choice;
switch(choice)
{case 1:
cout<<n1<<"/"<<n3<<"+"<<n2<<"/"<<n4<<"="<<n1*n4+n2*n3<<"/"<<n3*n4<<endl;
break;
case 2:
cout<<n1<<"/"<<n3<<"-"<<n2<<"/"<<n4<<"="<<n1*n4-n2*n3<<"/"<<n3*n4<<endl;
break;
case 3:
cout<<n1<<"/"<<n3<<"*"<<n2<<"/"<<n4<<"="<<n1*n2<<"/"<<n3*n4<<endl;
break;
case 4:
cout<<n1<<"/"<<n3<<"/"<<n2<<"/"<<n4<<"="<<n1*n4<<"/"<<n2*n3<<endl;
break;
default:
cout<<"your choice is invalid.\n";
break;
}
}
private:
int n1,n2,n3,n4;
};
void main()
{
rational num1,num2;
num1.ration();
num2.ration();
}

本程序的错误是那里?请各位指教

[alfxiao]

??

[ToUpdate]

up

[benny106]

改为一下还是不行啊.
#include<iostream.h>
class rational //定义一个类
{
public: //公有部分
rational() //定义一个构造函数,函数名与类同名
{
num()
{
int z1,z2,m1,m2;
cout<<"输入第一个数的分子。\n";
cin>>z1;
cout<<"输入第一个数的分母。\n";
cin>>m1;
cout<<"输入第二个数的分子。\n";
cin>>z2;
cout<<"输入第二个数的分母。\n";
cin>>m2;
}
void start()
{
int choice;
cout<<"请输入+,-,*,/\n1.+\n2.-\n3.*\n4./\n";
cin>>choice;
switch(choice)
{case 1:
cout<<n1<<"/"<<n3<<"+"<<n2<<"/"<<n4<<"="<<n1*n4+n2*n3<<"/"<<n3*n4<<endl;
break;
case 2:
cout<<n1<<"/"<<n3<<"-"<<n2<<"/"<<n4<<"="<<n1*n4-n2*n3<<"/"<<n3*n4<<endl;
break;
case 3:
cout<<n1<<"/"<<n3<<"*"<<n2<<"/"<<n4<<"="<<n1*n2<<"/"<<n3*n4<<endl;
break;
case 4:
cout<<n1<<"/"<<n3<<"/"<<n2<<"/"<<n4<<"="<<n1*n4<<"/"<<n2*n3<<endl;
break;
default:
cout<<"your choice is invalid.\n";
break;
}
}
}
private: //私有部分
int n1,n2,n3,n4;
};
void main()
{
rational num;
num.start();

}

[benny106]

谢谢大家帮忙.
现在好像有点思路了.
我在改一改吧.

[River_H]

#include <iostream.h>
#include "conio.h"

class rational
{
public:
void ration(int z1,int z2,int m1,int m2)
{
n1=z1;n2=z2;n3=m1;n4=m2;
}
rational()
{
cout<<"输入一个数的分子。\n";
cin>>n1;
cout<<"输入一个数的分母。\n";
cin>>n3;
cout<<"输入一个数的分子。\n";
cin>>n2;
cout<<"输入一个数的分母。\n";
cin>>n4;
}
void start()
{
int choice;
cout<<"请输入+,-,*,/\n1.+\n2.-\n3.*\n4./\n";
cin>>choice;
switch(choice)
{case 1:
cout<<n1<<"/"<<n3<<"+"<<n2<<"/"<<n4<<"="<<n1*n4+n2*n3<<"/"<<n3*n4<<endl;
break;
case 2:
cout<<n1<<"/"<<n3<<"-"<<n2<<"/"<<n4<<"="<<n1*n4-n2*n3<<"/"<<n3*n4<<endl;
break;
case 3:
cout<<n1<<"/"<<n3<<"*"<<n2<<"/"<<n4<<"="<<n1*n2<<"/"<<n3*n4<<endl;
break;
case 4:
cout<<n1<<"/"<<n3<<"/"<<n2<<"/"<<n4<<"="<<n1*n4<<"/"<<n2*n3<<endl;
break;
default:
cout<<"your choice is invalid.\n";
break;
}
}
private:
int n1,n2,n3,n4;
};
void main()
{
rational num1;

num1.start();

getch();
}

这样子试试

[weimenren]

d:\test\cpp1.cpp(7) : error C2065: 'num' : undeclared identifier
d:\test\cpp1.cpp(8) : error C2143: syntax error : missing ';' before '{'
d:\test\cpp1.cpp(20) : error C2601: 'start' : local function definitions are illegal
d:\test\cpp1.cpp(49) : error C2039: 'start' : is not a member of 'rational'

这是vc6.0编译的结果，我想你应该知道怎么修改

[battlet]

#include<iostream.h>
class rational //定?一个?
{
public: //公有部分
rational() //定?一个?造函数,函数名与?同名
{
int z1,z2,m1,m2;
cout<<"?入第一个数的分子。\n";
cin>>z1;
cout<<"?入第一个数的分母。\n";
cin>>m1;
cout<<"?入第二个数的分子。\n";
cin>>z2;
cout<<"?入第二个数的分母。\n";
cin>>m2;
}
void start()
{
int choice;
cout<<"??入+,-,*,/\n1.+\n2.-\n3.*\n4./\n";
cin>>choice;
switch(choice)
{
case 1:
cout<<n1<<"/"<<n3<<"+"<<n2<<"/"<<n4<<"="<<n1*n4+n2*n3<<"/"<<n3*n4<<endl;
break;
case 2:
cout<<n1<<"/"<<n3<<"-"<<n2<<"/"<<n4<<"="<<n1*n4-n2*n3<<"/"<<n3*n4<<endl;
break;
case 3:
cout<<n1<<"/"<<n3<<"*"<<n2<<"/"<<n4<<"="<<n1*n2<<"/"<<n3*n4<<endl;
break;
case 4:
cout<<n1<<"/"<<n3<<"/"<<n2<<"/"<<n4<<"="<<n1*n4<<"/"<<n2*n3<<endl;
break;
default:
cout<<"your choice is invalid.\n";
break;
}
}
private: //私有部分
int n1,n2,n3,n4;
};
void main()
{
rational num;
num.start();
}

这样可以啊。

[weimenren]

你的意思是要程序出你想要的结果？

[battlet]

void ration(int z1,int z2,int m1,int m2)
{
n1=z1;n2=z2;n3=m1;n4=m2;
}
num1.ration();
第一个:调用错误，

修改后,
num() 这个是什么？

[battlet]

修改如下：
#include<iostream.h>
class rational //定?一个?
{
public: //公有部分
rational() //定?一个?造函数,函数名与?同名
{
cout<<"?入第一个数的分子。\n";
cin>>n1;
cout<<"?入第一个数的分母。\n";
cin>>n2;
cout<<"?入第二个数的分子。\n";
cin>>n3;
cout<<"?入第二个数的分母。\n";
cin>>n4;
}
void start()
{
int choice;
cout<<"??入+,-,*,/\n1.+\n2.-\n3.*\n4./\n";
cin>>choice;
switch(choice)
{
case 1:
cout<<n1<<"/"<<n3<<"+"<<n2<<"/"<<n4<<"="<<n1*n4+n2*n3<<"/"<<n3*n4<<endl;
break;
case 2:
cout<<n1<<"/"<<n3<<"-"<<n2<<"/"<<n4<<"="<<n1*n4-n2*n3<<"/"<<n3*n4<<endl;
break;
case 3:
cout<<n1<<"/"<<n3<<"*"<<n2<<"/"<<n4<<"="<<n1*n2<<"/"<<n3*n4<<endl;
break;
case 4:
cout<<n1<<"/"<<n3<<"/"<<n2<<"/"<<n4<<"="<<n1*n4<<"/"<<n2*n3<<endl;
break;
default:
cout<<"your choice is invalid.\n";
break;
}
}
private: //私有部分
int n1,n2,n3,n4;
};
void main()
{
rational num;
num.start();
}

[leolance]

private:
int n1,n2,n3,n4,z1,m1;


然后
void main()
{
rational num1,num2;
num1.ration();
num2.ration();
}

ration的调用有问题，没有参数。