> For the complete documentation index, see [llms.txt](https://george-jen.gitbook.io/data-science-and-apache-spark/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://george-jen.gitbook.io/data-science-and-apache-spark/map-and-filter.md).

# map and filter

### map(func) and filter(func)

Both are first class functions. First class functions take function as input parameter or output as function.

#### Functional programming:

Programming focusing on a function is used as input parameter of another function or methods or as output of another function or method