Understanding pure functions
Pure functions are important in functional programming. They have two main features:
- Deterministic output: For any given input, a pure function will always yield the same output, making its behavior extremely predictable. This characteristic simplifies the process of testing and debugging since the output of the function is always consistent given the same set of inputs.
- No observable side effects: A pure function does not influence or is influenced by an external state. This means it doesn’t modify any external variables or data structures, or even carry out I/O operations. The function’s sole effect is the computation it performs and the result it delivers.
These two properties make pure functions similar to mathematical functions. A mathematical function, f(x) = y, produces a result, y, that relies solely on the input, x, and doesn’t alter or is altered by anything outside of the function. In programming, a pure...
