gcc Calc.cpp -lstdc ++


错误信息：


Calc.cpp：在构造函数''Calc :: Calc（）''中：

Calc.cpp：6：错误：在''this''中请求成员''a''，这是非

类类型''Calc * const''

Calc.cpp：7：错误：在''this''中请求成员''''，这是非

类类型''Calc * const''
Calc.cpp：在构造函数'Calc :: Calc（int，int）''中：

Calc.cpp：12：错误：请求成员''a' 'in''this''，这是非

类类型''Calc * const''

Calc.cpp：13：错误：请求成员' ''这''中的'b''，这是非b / b $ b $类类型''Calc * const''

Calc.cpp：在析构函数''Calc中::〜Calc（）''：

Calc.cpp：18：错误：请求成员a中的''这个''，这是非

类类型''Calc * const''

Calc.cpp：19：错误：请求对于''这个''中的成员''''，这是非

类类型''Calc * const''

Calc.cpp：成员function''int Calc :: plus（）''：

Calc.cpp：24：错误：在''this''中请求成员''a''，这是非

类类型''Calc * const''

Calc.cpp：24：错误：在''this''中请求成员''b''，这是非
类类型''Calc * const''

Calc.cpp：在成员函数''int Calc :: minus（）''中：

Calc.cpp：29：错误：在''this''中请求成员''''，这是非'
类类型''Calc * const''

Calc.cpp：29：错误：在''this''中请求成员''''，这是非

类类型''Calc * const ''

Calc.cpp：我n成员函数''int Calc :: multi（）''：

Calc.cpp：34：错误：在''this''中请求成员''a''，这是非 -

类类型''Calc * const''

Calc.cpp：34：错误：在''this''中请求成员''b''，是非b $ b类类型''Calc * const''

Calc.cpp：在成员函数''int Calc :: divide（）''：

Calc.cpp：39：错误：在''this''中请求成员''b''，这是非b / b
类型''Calc * const' '

Calc.cpp：41：错误：在''this''中请求成员''a''，这是非'
类类型''Calc * const''

Calc.cpp：41：错误：在''this''中请求成员''b''，这是非

类类型''Calc * const''

Calc.cpp：45：错误：请求''这个'中的成员'''''，这是非$ / $
类型''Calc * con st''

Calc.cpp：45：错误：在''this''中请求成员''a''，这是非'
class type' 'Calc * const''


我认为这些错误信息意味着''a''和'b''不是Calc

类的成员。为什么？


谢谢，

gcc Calc.cpp -lstdc++

Error Message:

Calc.cpp: In constructor ''Calc::Calc()'':
Calc.cpp:6: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:7: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In constructor ''Calc::Calc(int, int)'':
Calc.cpp:12: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:13: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In destructor ''Calc::~Calc()'':
Calc.cpp:18: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:19: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::plus()'':
Calc.cpp:24: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:24: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::minus()'':
Calc.cpp:29: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:29: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::multi()'':
Calc.cpp:34: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:34: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::divide()'':
Calc.cpp:39: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:41: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:41: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:45: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:45: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''

I think those error messages mean ''a'' and ''b'' are not members of Calc
class. Why is that?

Thanks,

Alexander Dong Back Kim写道：

Alexander Dong Back Kim wrote:

亲爱的，


我以前一直使用C ++编程语言，但转到C＃和

Java。几天前，我重新开始学习C ++，初学者心态非常好。我写了一个简单的类，gcc无法编译

类。有什么提示我不见了？

Dear all,

I used to use C++ programming language at all time but moved to C# and
Java. Few days ago, I restarted studying about C++ with a very
beginner''s mind. I wrote a simple class and gcc couldn''t compile the
class. Any hints that I''m missing?

查看编译器消息。 "这"是Calc * const类型，特别是

指针。你有这个的地方。你应该有this->。但是应该

这里是错误的词，因为你不需要使用this。在这里。

而不是this-> a = 0只需写a = 0。

Look at the compiler message. "this" is of type Calc* const, notably a
pointer. Where you have "this." you should have "this->". But "should"
is the wrong word here since you don''t need to use "this" at all here.
Rather than "this->a = 0" simply write "a = 0".

>

头文件：


#ifndef __Calc_h__

#define __Calc_h__


class Calc

{

private：

int a;

int b;

public：

Calc（）;

Calc （int a，int b）;


~Calc（）;


int plus（）;

int minus（）;

int multi（）;

int divide（）;

};


#endif


源文件：


#include" Calc.h"


Calc :: Calc（）

{

this.a = 0;

this.b = 0;

}


Calc :: Calc（int a，int b）

{

this.a = a;

this.b = b;

}


Calc ::〜计算（）

{

this.a = 0;

thi sb = 0;

}


int Calc :: plus（）

{

return this.a + this.b;

}


int Calc :: minus（）

{

返回this.a - this.b;

}


int Calc :: multi（）

{

返回this.a * this.b;

}


int Calc :: divide（）

{

if（this.b！= 0）

{

返回this.a / this.b;

}

否则如果（a！= 0）

{

返回this.b / this.a;

}

其他

{

返回0;

}

}


GCC命令：

>
Header File:

#ifndef __Calc_h__
#define __Calc_h__

class Calc
{
private:
int a;
int b;
public:
Calc();
Calc(int a, int b);

~Calc();

int plus();
int minus();
int multi();
int divide();
};

#endif

Source File:

#include "Calc.h"

Calc::Calc()
{
this.a = 0;
this.b = 0;
}

Calc::Calc(int a, int b)
{
this.a = a;
this.b = b;
}

Calc::~Calc()
{
this.a = 0;
this.b = 0;
}

int Calc::plus()
{
return this.a + this.b;
}

int Calc::minus()
{
return this.a - this.b;
}

int Calc::multi()
{
return this.a * this.b;
}

int Calc::divide()
{
if (this.b != 0)
{
return this.a / this.b;
}
else if (a != 0)
{
return this.b / this.a;
}
else
{
return 0;
}
}
GCC command:

gcc Calc.cpp -lddc ++
>
错误消息：


Calc.cpp：在构造函数''Calc :: Calc（）''中：

Calc.cpp：6 ：错误：请求成员'a''在''this''中，这是非

类类型''Calc * const''

Calc.cpp：7：错误：请求对于''这个''中的成员''''，这是非

类类型''Calc * const''

Calc.cpp：在构造函数中''Calc :: Calc（int，int）''：

Calc.cpp：12：错误：在''this''中请求成员''a''，这是非

类类型''Calc * const''

Calc.cpp：13：错误：在''this''中请求成员''b''，这是非

类类型''Calc * const''

Calc.cpp：在析构函数''Calc :: ~Calc（）''中：

Calc.cpp：18：错误：要求成员''a''在''this''中，这是非

类类型''Calc * const''

Calc.cpp：19：错误：在''this''中请求成员''b''，这是非b / b $ b $类类型''Calc * const ''

Calc.cpp：在会员傅nction''int Calc :: plus（）''：

Calc.cpp：24：错误：在''this''中请求成员''a''，这是非

类类型''Calc * const''

Calc.cpp：24：错误：在''this''中请求成员''b''，这是非
类类型''Calc * const''

Calc.cpp：在成员函数''int Calc :: minus（）''中：

Calc.cpp：29：错误：在''this''中请求成员''''，这是非'
类类型''Calc * const''

Calc.cpp：29：错误：在''this''中请求成员''''，这是非

类类型''Calc * const ''

Calc.cpp：在成员函数''int Calc :: multi（）''：

Calc.cpp：34：错误：请求成员'' a''in''this''，这是非

类类型''Calc * const''

Calc.cpp：34：错误：请求成员''''在''这个' ，这是非

类类型''Calc * const''

Calc.cpp：在成员函数''int Calc :: divide（）''中：

Calc.cpp：39：错误：在''this''中请求成员'''''，这是非

类类型''Calc * const''

Calc.cpp：41：错误：在''this''中请求成员''a''，这是非

类类型' 'calc * const''

Calc.cpp：41：错误：请求''这个'中的成员''''，这是非

类类型''Calc * const''

Calc.cpp：45：错误：请求''这个'中的成员'''''，这是非

类类型''Calc * const''

Calc.cpp：45：错误：在''this''中请求成员''a''，这是非

类类型''Calc * const''


我认为这些错误消息意味着''a''和'b''不是Calc的成员

cla SS。为什么？


谢谢，

gcc Calc.cpp -lstdc++

Error Message:

Calc.cpp: In constructor ''Calc::Calc()'':
Calc.cpp:6: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:7: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In constructor ''Calc::Calc(int, int)'':
Calc.cpp:12: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:13: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In destructor ''Calc::~Calc()'':
Calc.cpp:18: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:19: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::plus()'':
Calc.cpp:24: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:24: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::minus()'':
Calc.cpp:29: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:29: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::multi()'':
Calc.cpp:34: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:34: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp: In member function ''int Calc::divide()'':
Calc.cpp:39: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:41: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:41: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:45: error: request for member ''b'' in ''this'', which is of non-
class type ''Calc* const''
Calc.cpp:45: error: request for member ''a'' in ''this'', which is of non-
class type ''Calc* const''

I think those error messages mean ''a'' and ''b'' are not members of Calc
class. Why is that?

Thanks,