Functional Programming

Introduction

This page is meant to give an overview of terms associated with functional programming and used with other languages like scala, kotlin, javascript.

Pure Functions

Introduction

• They will always produce the same answer with the same input.
• They will not produce side effects

function plus(a, b) {
  return a + b;
}

Impure and Side Effect

Given

let str = "some thing"

let f_pure = function(_input) {
  let _output = _input.toUpperCase()
  return _output
}

let f_impure = function(_input) {
  let _output = _input.toUpperCase()
  str = _output
  return _output
}

The f_pure will return what was passed in and modify no other data. However the f_impure does modify str outside of the scope of the function (side effect) and therefore is not considered to be a pure function.

Statics vs Pure

The difference between static and pure functions is that a static can be a void and can increment other static values.