Implementation (computational constructs)Data flow

The term data flow is used to describe how data moves between sub-programs in a software development language. Data flow is often identified during design and implemented using parameter passing.

Data either flows out of a sub-program or into a sub-program.

IN - Data is passed into a sub-program

OUT - Data is passed out of a sub-program

Some programmers also use:

IN/OUT - This definition is used when data is passed IN, is altered and the altered value is passed OUT

Some programmers don't use IN/OUT as part of their design, preferring to only use OUT once and IN any other time the value is passed, regardless of whether it has been altered or not.