As we know, for main, it's so common to see it looks like below:
int main()
{
// do your work.
return 0;
}
At least for a console application, the returned value 0 here can be consumed later in script tool using below lines (into a bat file):
@echo off
ConsoleApplication1.exe arg1 arg2
echo Result is “%errorlevel%”
pause
Here, “%errorlevel%” will get 0 which is main function's return value.