C++ Hello World 体系结构的 undefined symbol x86_64 :

Question

应该很简单，但是当我编译 C++ Hello World 代码时返回一堆 undefined symbol 错误。

// my first program in C++
#include <iostream>
using namespace std;

int main ()
{
  cout << "Hello World!";
  return 0;
}

我是这样编译的:打开终端，cd到目录，gcc hello.cpp

然后我得到了错误。有什么想法吗？我觉得我可能已经破坏了某些东西……或者我只是遗漏了一些非常明显的东西。非常感谢任何帮助!

这里是错误:

Undefined symbols for architecture x86_64:
"std::cout", referenced from:
      _main in ccfUAf5i.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 ccfUAf5i.o
  "std::ios_base::Init::Init()", referenced from:
      __static_initialization_and_destruction_0(int, int)in ccfUAf5i.o
  "std::ios_base::Init::~Init()", referenced from:
      ___tcf_0 in ccfUAf5i.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

Answer 1

你需要使用g++来编译和链接C++代码:

g++ hello.cpp -o hello

或者完全符合 Stack Overflow 标准:

g++ -W -Wall -Werror -pedantic -o hello hello.cpp