| --- |
| page_title: coalescelist - Functions - Configuration Language |
| description: |- |
| The coalescelist function takes any number of list arguments and returns the |
| first one that isn't empty. |
| --- |
| |
| # `coalescelist` Function |
| |
| `coalescelist` takes any number of list arguments and returns the first one |
| that isn't empty. |
| |
| ## Examples |
| |
| ``` |
| > coalescelist(["a", "b"], ["c", "d"]) |
| [ |
| "a", |
| "b", |
| ] |
| > coalescelist([], ["c", "d"]) |
| [ |
| "c", |
| "d", |
| ] |
| ``` |
| |
| To perform the `coalescelist` operation with a list of lists, use the `...` |
| symbol to expand the outer list as arguments: |
| |
| ``` |
| > coalescelist([[], ["c", "d"]]...) |
| [ |
| "c", |
| "d", |
| ] |
| ``` |
| |
| ## Related Functions |
| |
| * [`coalesce`](/language/functions/coalesce) performs a similar operation with string |
| arguments rather than list arguments. |
