What are the core concepts in functional programming?

Question

In object-oriented programming, we might say the core concepts are:

1. encapsulation
2. inheritance,
3. polymorphism

What would that be

Answer 1

Though the question is older, thought of sharing my view as reference.

• Core Concept in FP is "FUNCTION"
• FP gives KISS(Keep It Simple Sxxxxx) programming paradigm (once you get the FP ideas, you will literally start hating the OO paradigm)

• Here is my simple FP comparison with OO Design Patterns. Its my perspective of seeing FP and pls correct me if there is any discrepancy from actual.