> For the complete documentation index, see [llms.txt](https://cs.brash.ca/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cs.brash.ca/unit-4.md).

# Unit 4: Functions

- [Functional Programming](https://cs.brash.ca/unit-4/functional-programming.md)
- [User Defined Functions](https://cs.brash.ca/unit-4/user-defined-functions.md): Writing your own functions gives the ability to reuse code.
- [Hoisting and Scope](https://cs.brash.ca/unit-4/user-defined-functions/notes.md)
- [Calling a JS Function](https://cs.brash.ca/unit-4/calling-a-js-function.md): Interaction between HTML and Javascript requires a function to be called.