Assigning a variable

Variables are placeholders for values that change.

Variables output values in your snippets. Variable names are denoted by double curly braces: {{ and }}. To render the content of a variable called title with the value hello world:

<p>{{ title }}</p>

<p>hello world</p>

Initializing variables

You can initialize variables with the assign or capture tags.

assign

Creates a new variable.

{% assign foo = "bar" %}

capture

Captures the string inside of the opening and closing tags and assigns it to a variable. Variables created through capture are strings.

{% capture foo %}I am being captured.{% endcapture %}

Types

There are five variable types: string, number, boolean, nil, and array.

String

Declare a string by wrapping a variable’s value in single (') or double quotes ("):

{% assign my_string = "Hello World!" %}

Number

Numbers include floats and integers:

{% assign my_int = 25 %}
{% assign my_float = 3.14159 %}

Boolean

Booleans are either true or false. No quotations are necessary when declaring a boolean:

{% assign foo = true %}
{% assign bar = false %}

nil

nil is a special empty value that is returned when we have no results. It is not a string with the characters “nil”.

nil is treated as false in the conditions of if blocks and other tags that check the truthfulness of a statement.

Tags or outputs that return nil will not print anything to the page.

<p>The current user is {{ foo }}</p>

<p>The current user is </p>

Arrays

Arrays hold lists of variables of any type. You can use square bracket [ ] notation to access a specific item in an array, and array indexing starts at zero.

<!-- if users = "Tobi", "Laura", "Tetsuro", "Adam" -->
{{ users[0] }}
{{ users[1] }}
{{ users[3] }}

Tobi
Laura
Adam

You cannot initialize arrays. You can, however, use the split filter to break a string into an array of substrings.

Truthy and falsey

Anything that returns true in a conditional is called truthy. Anything that returns false in a conditional is called falsy. All variables can be described as either truthy or falsy.

All values are truthy except nil and false, even empty strings, arrays, and zero.