GNU GCC compilor error “multiple definition of main”

Question

I am new to ubuntu, now I need to develop my assignment in C++. I am using codeblocks IDE to write c++ programs. Whenever I compile something in it, it gives these errors:

Answer 1

It seems that your IDE is not just compiling one single file, but another one which also contains a definition of the main function. Please check out how many files are being compiled.

In addition, your compiled is treating all the warnings as errors (-Werror) or disable this flag.