Array Filters

Filters for manipulating arrays, collections, and lists.

A list prints nothing in {{ }}: the filters that return a list give a value to loop over or to pass on, for example to join. The comments below show that value.

first, last, length, reverse and slice work on strings too: {{ 'abc'|first }} gives a.

Accessing Elements

Filter	Arguments	Description
first	—	Get first element
last	—	Get last element
length	—	Get count
keys	—	Get array keys
values	—	Get array values

{{ posts|first }}
{{ posts|last }}
{{ posts|length }}
{{ data|keys }}
{{ data|values }}

Joining

Filter	Arguments	Description
join	glue, and	Join elements into string
list	first_delimiter, second_delimiter	Human-readable list

join Arguments:

• glue — Separator between items (default: '')
• and — Separator before last item (optional)

{{ categories|join(', ') }}                    <!-- A, B, C -->
{{ categories|join(', ', ' and ') }}           <!-- A, B and C -->
{{ tags|join(' | ') }}

list Arguments:

• first_delimiter — Separator between items (default: ',')
• second_delimiter — Separator before last item (default: ' and')

{{ names|list }}                               <!-- A, B and C -->
{{ names|list(';', ' or') }}                   <!-- A; B or C -->

As in Timber, list adds a space after each separator.

Slicing

Filter	Arguments	Description
slice	start, length, preserve_keys	Extract portion
batch	size, fill, preserve_keys	Group into batches

slice Arguments:

• start — Start index (default: 0)
• length — Number of items (optional)
• preserve_keys — Keep original numeric keys (default: false); text keys are always kept

{{ items|slice(0, 3) }}                        <!-- First 3 items -->
{{ items|slice(2) }}                           <!-- Skip first 2 -->
{{ items|slice(-2) }}                          <!-- Last 2 items -->

batch Arguments:

• size — Items per batch (default: 1)
• fill — Value to fill incomplete batch (optional)
• preserve_keys — Keep original keys (default: true, as in Twig)

{{ items|batch(3) }}                           <!-- [[1,2,3], {3:4, 4:5, 5:6}] -->
{{ items|batch(3, null, false) }}              <!-- [[1,2,3], [4,5,6]] -->
{{ items|batch(3, 'empty') }}                  <!-- Fill with 'empty' -->

Keys are kept by default, so the second batch starts at key 3, not 0: pass false as the third argument to number each batch from 0, or loop over each batch rather than reading row[0].

Sorting

Filter	Arguments	Description
sort	arrow	Sort array
reverse	preserve_keys	Reverse order
shuffle	—	Randomize order

{{ numbers|sort }}
{{ items|sort((a, b) => a.date <=> b.date) }}
{{ items|reverse }}
{{ items|shuffle }}

sort keeps each item's key, as in Twig: [3, 1, 2]|sort gives {1: 1, 2: 2, 0: 3}, so a key-value loop over it still reads the original keys. Add |values to number the items from 0 again, for example before json_encode.

Transformation

Filter	Arguments	Description
filter	arrow	Keep matching elements
map	arrow	Transform each element
reduce	arrow, initial	Reduce to single value
find	arrow	Find first matching element
column	name, index	Extract column
merge	array	Merge arrays
array	—	Ensure value is array

filter

Keep elements where the arrow function returns true. The kept elements keep their keys, as in Twig: add |values to number them from 0 again.

{{ items|filter(p => p.active) }}
{{ posts|filter(p => p.meta('featured')) }}
{{ items|filter }}                             <!-- Remove falsy values -->
{{ [1, 2, 3, 4]|filter(v => v > 2)|values }}   <!-- [3, 4] -->

map

Transform each element.

{{ posts|map(p => p.title) }}
{{ items|map(i => i.name) }}

reduce

Reduce array to single value.

{{ items|reduce((carry, item) => carry + item.price, 0) }}
{{ numbers|reduce((a, b) => a + b, 0) }}

find

Find first element the arrow function matches.

{{ items|find(i => i.id == 5) }}
{{ posts|find(p => p.meta('featured')) }}

column

Extract column values (like PHP's array_column).

{{ users|column('name') }}                     <!-- ['John', 'Jane'] -->
{{ users|column('name', 'id') }}               <!-- {1: 'John', 2: 'Jane'} -->

merge

Merge two arrays.

{{ categories|merge(tags) }}

array

Ensure value is array (useful for safe looping).

{{ value|array }}                              <!-- Wraps non-array in array -->

WordPress Filter

Filter	Arguments	Description
wp_list_filter	args, operator	Filter using wp_list_filter()

Arguments:

• args — Filter criteria as object
• operator — 'AND' (default), 'OR', or 'NOT' to keep the items that match none of the criteria

{{ posts|wp_list_filter({'post_status': 'publish'}) }}
{{ items|wp_list_filter({'active': true, 'featured': true}, 'AND') }}

Common Patterns

Comma-separated list

{{ post.categories|map(c => c.name)|join(', ') }}

First 3 featured items

{{ posts|filter(p => p.meta('featured'))|slice(0, 3) }}

Count matching items

{{ posts|filter(p => p.post_status == 'publish')|length }}

One field of each row

Repeater and group fields return a list of hashes; column picks one field of each:

{{ post.meta('team')|column('name')|join(', ') }}

Check if array contains item

{{ 'admin' in user.roles ? 'Admin' : 'User' }}