Impure Functions
Impure functions are functions in programming that produce side effects or depend on external state, making their output not solely determined by their input arguments. Side effects can include modifying global variables, performing I/O operations, or changing mutable data structures. This contrasts with pure functions, which always return the same output for the same input and have no side effects.
Developers should learn about impure functions to understand functional programming principles and manage side effects effectively in code, especially in languages like JavaScript, Python, or Haskell. They are essential for tasks that inherently involve side effects, such as file handling, database interactions, or user input processing, but should be used judiciously to avoid bugs and improve testability.