Which of the following is NOT a characteristic of a function in programming?

The correct answer is that functions cannot be recursive. This statement is not a characteristic of functions in programming. In fact, many programming languages support recursive functions, which are functions that call themselves in order to solve a problem. Recursive functions are a powerful concept, allowing for elegant solutions to problems that can be broken down into smaller, simpler subproblems.

The other options describe true characteristics of functions. For instance, functions can indeed return values, which allows them to provide output that can be used in further computations. Additionally, functions may have parameters, enabling them to accept inputs, making them more versatile and reusable, as the same function can process different inputs. While it's often possible for functions to modify global state depending on the programming language and context, this action can lead to side effects that are generally avoided in well-structured programming due to concerns about maintainability and predictability. Therefore, understanding that a function can be recursive helps clarify its definition and potential applications in programming.