Arrays

An array is a list of values in a single variable. You create an array by providing multiple values within brackets ([...]) and separating them with commas.

Arrays are numerically indexed starting with zero. You can access individual array elements with a dot (.) or brackets ([]).

For example:

{% set colors = ['red','green','blue'] %}
Item 0 is {{colors.0}}
Item 2 is {{colors[2]}}

Item 0 is red
Item 2 is blue

Objects

Objects are similar to arrays, except that the items are indexed with a key and you wrap them in curly braces ({}):

{% set person = {
	"first_name": "William",
	"last_name": "Portcullis",
	"age": 63
} %}
{{person.first_name}} {{person.last_name}} is {{person.age}}.

William Portcullis is 63.

Dynamic keys

You can specify an object key with a variable by using brackets ([]):

{% set person = {
	"first_name": "William",
	"last_name": "Portcullis",
	"age": 63
} %}
{% set key = 'first_name' %}
His name is {{person[key]}}.

His name is William.

Modifying arrays and objects

You can use the dict_set() function to quickly modify, append, or remove items from an array or object.

You can set deeply nested keys in a single line using dot-notation:

{% set var = {"group": {}} %}
{% set var = dict_set(var, 'group.name', 'Support') %}
{% set var = dict_set(var, 'group.manager.name.first', 'Kina') %}
{% set var = dict_set(var, 'group.manager.name.last', 'Halpue') %}
{{var|json_encode|json_pretty}}

{
  "group": {
    "name": "Support",
    "manager": {
      "name": {
        "first": "Kina",
        "last": "Halpue"
      }
    }
  }
}

Append items to an array by adding .[] to the key:

{% set var = {"group": {}} %}
{% set var = dict_set(var, 'group.name', 'Support') %}
{% set var = dict_set(var, 'group.members.[]', 'Kina Halpue') %}
{% set var = dict_set(var, 'group.members.[]', 'William Portcullis') %}
{% set var = dict_set(var, 'group.members.[]', 'Steven Emplois') %}
{{var|json_encode|json_pretty}}

{
  "group": {
    "name": "Support",
    "members": [
      "Kina Halpue",
      "William Portcullis",
      "Steven Emplois"
    ]
  }
}

Append to nested arrays:

{% set var = [1,2,[3,4,[5,6]]] %}
{% set var = dict_set(var, '2.2.[]', 7) %}
{% set var = dict_set(var, '2.2.[]', 8) %}
{% set var = dict_set(var, '2.3', 9) %}
{{var|json_encode|json_pretty}}

[
  1,
  2,
  [
    3,
    4,
    [
      5,
      6,
      7,
      8
    ],
    9
  ]
]

Compute the difference of two arrays

The array_diff() function returns the items in the second array that are not present in the first array:

{% set arr1 = ['Apple', 'Google', 'Microsoft'] %}
{% set arr2 = ['Apple', 'Microsoft', 'Cerb'] %}
{% set diff = array_diff(arr2, arr1) %}
These are new: {{diff|join(', ')}}

These are new: Cerb