Functional Programming

Declarative Programming Paradigm

Composition math

(f ° g)(x) = f(g(x))
           = f(2x)
           = 2x + 1

• First-class function is treated as a variable.
• Pure functions is a function that works just with its inputs and doesn't affect the parameters.
• Recursive functions is a function that calls itself during its execution.
• Anonymous function is a function definition that is not bound to an entity.
• Higher-order functions are functions that can either take other functions as arguments or return them as results.

What else?

• Immutable variables
• Non-strict vs strict evaluation
• Statements
• Referential transparency
• Data structures in FP
• Pattern matching