What should every program end with according to standard coding practices?

In standard coding practices, every program should end with an exit code. An exit code is a value returned by a program to the operating system upon its completion. It indicates the status of the program's execution; a return value of zero typically signifies success, while any non-zero value indicates an error or abnormal termination.

Including an exit code helps to communicate the outcome of the program to any processes that may have launched it. This is particularly important in environments where programs are automated or chained together, as other scripts or programs can make decisions based on the exit code received.

While the return statement in a programming language like C or C++ is also important, particularly for functions, it primarily serves to return a value to the calling function, not necessarily to the operating system. The close command refers to file management, ensuring that files are properly closed after operations, but doesn't inherently signify the conclusion of program execution. The end statement is not a standard requirement across programming languages and is therefore less relevant in a general context.

Thus, focusing on the requirement for conveying program completion status, an exit code is essential for standard coding practices.