Eclipse C++ on OSX Cant Build - c++

Question

I am new to coding and C++ and have just installed C++ and XCode on my computer. I have made Mac OSX GCC my preferred tool chain.
I can't seem to even get a simple Hello World program to run, I really need some help here, I've posted before and looked around but nothing seems to help me.
Code:
#include <iostream>
using namespace std;
int main() {
cout << "Hello world \n";
return 0;
}
Error after clicking on build all:
12:38:22 **** Incremental Build of configuration Debug for project Test1 ****
make all
Building file: ../test.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"test.d" -MT"test.o" -o "test.o" "../test.cpp"
Finished building: ../test.cpp
Building target: Test1
Invoking: MacOS X C++ Linker
g++ -o "Test1" ./test.o
Undefined symbols for architecture x86_64:
"_main", referenced from:
implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [Test1] Error 1
12:38:37 Build Finished (took 15s.286ms)

Answer 1

You mentioned that you just installed XCode. If you are looking to get started with C++ programming, using XCode will make your experience more satisfying and learning curve faster than if you use Eclipse. XCode is a "native" IDE on Mac.
Having said this, I understand there may be reasons to use Eclipse, e.g. if you expect to start programming on non-Apple platforms in a very near future, or want to familiarize yourself with Eclipse as the IDE to do Android programming. However, if you are going to be on Mac for awhile and want to pick up C++ faster, I would strongly recommend sticking with XCode.
Now, the error you show could be because the file has not been saved, as suggested by one of the commenters. That's exactly the error you get if main() is missing.