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

Abstraction, the process of making a function by parameterizing over some part of an expression.

Application, the process of evaluating a function by replacing its parameters with specific values.

At some level, that's all there is to it.