github.com/anth0d/nomad@v0.0.0-20221214183521-ae3a0a2cad06/website/content/docs/job-specification/hcl2/functions/collection/lookup.mdx (about) 1 --- 2 layout: docs 3 page_title: lookup - Functions - Configuration Language 4 description: The lookup function retrieves an element value from a map given its key. 5 --- 6 7 # `lookup` Function 8 9 `lookup` retrieves the value of a single element from a map, given its key. 10 If the given key does not exist, a the given default value is returned instead. 11 12 ```hcl 13 lookup(map, key, default) 14 ``` 15 16 ## Examples 17 18 ```shell-session 19 > lookup({a="ay", b="bee"}, "a", "what?") 20 ay 21 > lookup({a="ay", b="bee"}, "c", "what?") 22 what? 23 ``` 24 25 ## Related Functions 26 27 - [`element`](/docs/job-specification/hcl2/functions/collection/element) retrieves a value from a _list_ given its _index_.