In dataflow programming, when a value changes, what happens to dependent values?

• A. They stay the same
• B. They are recalculated
• C. They never change
• D. They cause compile error

Answer: (B)

In dataflow programming, values move through a graph of dependencies, so when an input value changes, the change propagates to every value that depends on it and those dependent values are recalculated to reflect the new inputs. This ensures the overall system remains consistent with the latest data. For example, if a value z is defined as z = x + y and x changes, z is recomputed using the new x value. That’s why dependent values are recalculated. Staying the same would ignore the new input, and never changing would violate the dataflow model; a compile error isn’t about runtime updates of data, and while some implementations may cache or lazily update results, the intended behavior in dataflow is to recompute to stay current.