C++ 5th edition--chapter 1

1.1 return code for main function 

--c++/c never define no return main function. we should not write main function like "void main()", even most of compiler will add "return 0" statement at the end of the main function automatically.
 --return 0 indicate that the program run successfully.
 --retnrn -1 indicate that the program run fail.
 --echo %ERRORLEVEL% to see the return status.
 --AA.exe && dir, if AA.exe run successfully, then execute dir command (for window plateform)
 --AA.exe || dir, if AA.exe run fail, then execute dir command (for window plateform)

1.2 input/output

--c++ language does not define any statements to do input or output.

--4 object, cin, cout, cerr, clog