Julia is first and foremost a functional language because computations and data transformations are done through functions; they are first-class citizens in Julia. Programs are structured around defining functions and to overload them for different combinations of argument types. This chapter discusses this keystone concept, covering the following topics:
- Defining functions
- Optional and keyword arguments
- Anonymous functions
- First-class functions and closures
- Recursive functions
- Broadcasting
- Map, filter, and list comprehensions
- Generic functions and multiple dispatch
