我想在Mac上编写非常简单的C++程序,但出现错误。我没有使用C++(和gcc)的丰富经验,网络上的简单指南也没有讨论此主题。
请看一下我简单的hello world程序:
erik2:~[03:38 pm]$ cat hw.cpp
#include <iostream>
int main ()
{
cout<<"Hello World!";
return 0;
}
erik2:~[03:38 pm]$ gcc hw.cpp
hw.cpp: In function ‘int main()’:
hw.cpp:5: error: ‘cout’ was not declared in this scope
到现在为止(非常感谢)响应答案,我放回了(!) namespace 声明,但这并不会成功:
erik2:~[03:51 pm]$ cat hw.cpp
using namespace std;
#include <iostream>
int main ()
{
cout<<"Hello World!";
return 0;
}
erik2:~[03:51 pm]$ gcc hw.cpp
Undefined symbols:
"___gxx_personality_v0", referenced from:
___gxx_personality_v0$non_lazy_ptr in ccphDFtO.o
"std::ios_base::Init::~Init()", referenced from:
___tcf_0 in ccphDFtO.o
"std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)", referenced from:
_main in ccphDFtO.o
"std::ios_base::Init::Init()", referenced from:
__static_initialization_and_destruction_0(int, int)in ccphDFtO.o
"std::cout", referenced from:
__ZSt4cout$non_lazy_ptr in ccphDFtO.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
最佳答案
您需要添加
using namespace std;
或限定您使用该 namespace 中的符号
std::cout << "Hello, world!";
因此,使符号可见(并且您还想添加换行符...。)。
关于c++ - 在Mac上编译C++代码,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/5582154/