Function - Pure Function
Table of Contents
1 - About
Pure functions are called pure because they do not attempt to change their inputs, and always return the same result for the same inputs.
The result is then predictable.
Pure function take data and transform it, without modifying any shared state, meaning there is no side effects besides returning a value.
They are mostly used in functional programming.
2 - Articles Related
3 - Example
Pure
function sum(a, b) {
return a + b;
}
Not Pure
function withdraw(account, amount) {
account.total -= amount;
}
4 - Data Structure
Pure functional data structures - Purely Functional Data Structures - Chris Okasaki - September 1996 - CMU-CS-96-177 (PDF)