mirror of
https://github.com/gohugoio/hugo.git
synced 2024-11-14 20:37:55 -05:00
46 lines
1.5 KiB
Markdown
46 lines
1.5 KiB
Markdown
---
|
|
title: collections.Union
|
|
description: Given two arrays or slices, returns a new array that contains the elements that belong to either or both arrays/slices.
|
|
categories: []
|
|
keywords: []
|
|
action:
|
|
aliases: [union]
|
|
related:
|
|
- functions/collections/Complement
|
|
- functions/collections/Intersect
|
|
- functions/collections/SymDiff
|
|
- functions/collections/Union
|
|
returnType: any
|
|
signatures: [collections.Union SET1 SET2]
|
|
aliases: [/functions/union]
|
|
---
|
|
|
|
Given two arrays (or slices) A and B, this function will return a new array that contains the elements or objects that belong to either A or to B or to both.
|
|
|
|
```go-html-template
|
|
{{ union (slice 1 2 3) (slice 3 4 5) }}
|
|
<!-- returns [1 2 3 4 5] -->
|
|
|
|
{{ union (slice 1 2 3) nil }}
|
|
<!-- returns [1 2 3] -->
|
|
|
|
{{ union nil (slice 1 2 3) }}
|
|
<!-- returns [1 2 3] -->
|
|
|
|
{{ union nil nil }}
|
|
<!-- returns an error because both arrays/slices have to be of the same type -->
|
|
```
|
|
|
|
## OR filter in where query
|
|
|
|
This is also very useful to use as `OR` filters when combined with where:
|
|
|
|
```go-html-template
|
|
{{ $pages := where .Site.RegularPages "Type" "not in" (slice "page" "about") }}
|
|
{{ $pages = $pages | union (where .Site.RegularPages "Params.pinned" true) }}
|
|
{{ $pages = $pages | intersect (where .Site.RegularPages "Params.images" "!=" nil) }}
|
|
```
|
|
|
|
The above fetches regular pages not of `page` or `about` type unless they are pinned. And finally, we exclude all pages with no `images` set in Page parameters.
|
|
|
|
See [intersect](/functions/collections/intersect) for `AND`.
|