#include<iostream>
using namespace std;
void other();
namespace n1;
{
int x = 1;
}
namespace n2;
{
int x = 2
}
int main()
{
using namespace n1;
cout<< x <<endl;
{
int x = 4;
cout<< x <<","<<n1:: x <<endl;
}
using n2::x;
cout<< x <<endl;
other();
return 0;
}
void other()
{
using namespace n2;
cout<< x <<endl;
{
int x = 4;
cout<< x << ","<<n1::x<<","<<n2::x<<endl;
}
using n2::x<<endl;
}

namespace n1{ }
不要在n1后面加分号
最后那一行不清楚，不过改成cout<<n2::x<<endl;可以运行

更正一下，还有一个错误查不出来；谁可以告诉我吗？谢谢！


#include<iostream>
using namespace std;
void other();
namespace n1
{
int x = 1;
}
namespace n2
{
int x = 2;
}
int main()
{
using namespace n1;
cout<< x <<endl;
{
int x = 4;
cout<< x <<","<<n1:: x <<endl;
}
using n2::x;
cout<< x <<endl;
other();
return 0;
void other()
{
using namespace n2;
cout<< x <<endl;
{
int x = 4;
cout<< x << ","<<n1::x<<","<<n2::x<<endl;
}
using n2::x;
cout<< x <<endl;
}

下面分别是两个编译器的结果：
C ++ builder 6:
[C++ Error] Unit1.cpp(25): E2141 Declaration syntax error
[C++ Error] Unit1.cpp(36): E2139 Declaration missing ;
[C++ Error] Unit1.cpp(36): E2134 Compound statement missing }



VC ++ 6.0:
Compiling...
Cpp1.cpp
C:\Documents and Settings\Administrator\My Documents\Microsoft Visual C++\Cpp1.cpp(25) : error C2601: 'other' : local function definitions are illegal
C:\Documents and Settings\Administrator\My Documents\Microsoft Visual C++\Cpp1.cpp(35) : fatal error C1004: unexpected end of file found
Error executing cl.exe.

Cpp1.obj - 2 error(s), 0 warning(s)

我来说一说，嘿嘿：
#include<iostream>
using namespace std;
void other();
namespace n1;//这里不加分号
{
int x = 1;
}
namespace n2;//这里不加分号
{
int x = 2//这里需要加分号
}
int main()
{
using namespace n1;
cout<< x <<endl;
{
int x = 4;
cout<< x <<","<<n1:: x <<endl;
}
using n2::x;
cout<< x <<endl;
other();
return 0;
}
void other()
{
using namespace n2;
cout<< x <<endl;
{
int x = 4;
cout<< x << ","<<n1::x<<","<<n2::x<<endl;
}
using n2::x<<endl;//这里去掉<<endl
}
我这样运行就OK了，你试一下吧。

嘿嘿 ，谢谢。可以啦

还可以帮忙看看这个程序吗？
Microsoft Visual C++\Cpp1.cpp(33) : error C2872: 'y' : ambiguous symbol


#include<iostream>
using namespace std;
void other();
void another();
int x = 10;
int y;
int main()
{
cout<< x <<endl;
{
int x =4;
cout<< x <<endl;
cout<< y <<endl;
}
other();
another();
return 0;
}
void other()
{
int y =1;
cout<< "other"<< x <<","<< y <<endl;
}
#include<iostream>
using namespace std;
extern int x;
namespace
{
int y = -4;
}
void another()
{
cout<<"another():"<< x <<","<< y <<endl;
}