Why Am I Getting 'Undefined Symbols' Errors When Compiling Simple C Code on macOS?

Error Compiling Simple C Code

Question:
I am receiving an error when compiling a basic C program on macOS Lion.

Code:

#include <iostream>

using namespace std;

int main(int argc, char *argv[])
{
    for (int i = 0; i < 10; i++)
    {
        cout << "hi";
        cout << endl;
    }

    return 0;
}

Compilation Command:

cc main.cpp

Error:

Undefined symbols for architecture x86_64:
  "std::cout", referenced from:
      _main in ccBdbc76.o
  "std::basic_ostream<char, std::char_traits<char> > &amp; std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> > &amp;, char const*)", referenced from:
      _main in ccBdbc76.o
  "std::basic_ostream<char, std::char_traits<char> > &amp; std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> > &amp;)", referenced from:
      _main in ccBdbc76.o
  "std::basic_ostream<char, std::char_traits<char> >::operator<< (std::basic_ostream<char, std::char_traits<char> > &amp; (*)(std::basic_ostream<char, std::char_traits<char> > &amp;))", referenced from:
      _main in ccBdbc76.o
  "std::ios_base::Init::Init()", referenced from:
      __static_initialization_and_destruction_0(int, int)in ccBdbc76.o
  "std::ios_base::Init::~Init()", referenced from:
      ___tcf_0 in ccBdbc76.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

Answer:

This type of error typically occurs when the C code is compiled using the C front-end. While the C compiler understands and compiles the file as C , it fails during linking due to missing references to the C libraries. To resolve this issue, ensure that you are using the C compiler instead. Replace cc with g or clang when compiling the code:

g++ main.cpp
clang++ main.cpp

Using the correct C compiler links the code with the necessary libraries and resolves the undefined symbol errors.

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