What does a program listing contain?

A program listing typically contains the text representation of a program’s source code, which includes the actual code written by the programmer along with any internal documentation and comments that clarify how the code works. This documentation is essential for understanding the functionality of the program, especially for future maintenance or for other programmers who may work on the code later.

Including formatting in a program listing helps maintain readability, making it easier to follow the logic of the code. Good formatting practices, such as indentation and organization, allow programmers to quickly identify the structure of loops, conditionals, and other control flow elements.

Compiled object code refers to machine-readable code that is generated from the source code but does not include the human-readable format necessary for understanding the program's logic. Essential code without comments would limit the clarity and accessibility of the code, particularly for collaborative environments. A visual representation of the code may aid in understanding but does not convey the complete textual information necessary for actual programming tasks. Therefore, a comprehensive program listing must include both the source code and relevant documentation to be truly effective.