---
title: "Conditional Logic"
slug: "liquid-tags-conditional-logic"
updated: 2026-03-24T13:29:31Z
published: 2026-03-24T13:29:31Z
canonical: "academy.insiderone.com/liquid-tags-conditional-logic"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://academy.insiderone.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Conditional Logic

Conditional logic controls which content is rendered based on whether a given condition evaluates to *true* or *false*. In Liquid, this is implemented through {% if %}, {% elsif %}, {% else %}, and {% unless %} tags, allowing templates to produce different outputs depending on the state of a variable or expression. This enables dynamic, personalized content without duplicating template code.

## Truthy / Falsy

Only nil, false, and "" are treated as false. Everything else, including 0, " ", and empty arrays ([]), is truthy.

```plaintext
{# Wrong — 0 IS truthy, the "else" branch never runs when count = 0 #}
{% if count %}
  You have {{ count }} items.
{% else %}
  No items.
{% endif %}

{# Correct #}
{% if count > 0 %}
  You have {{ count }} items.
{% else %}
  No items.
{% endif %}
```

## Check for blank before other conditions

Always check that a variable has a value before comparing it, to avoid unexpected behavior with unset attributes.

```plaintext
{# Safe — checks existence first #}
{% if c_loyalty_tier != blank and c_loyalty_tier == "gold" %}
  Gold offer.
{% endif %}

{# Simpler when the comparison already handles blank safely #}
{% if c_loyalty_tier == "gold" %}
  Gold offer.
{% endif %}
```

## Nested conditions

Use nested if blocks for logical grouping (parentheses are not supported).

```plaintext
{% if age >= 18 %}
  {% if c_loyalty_tier == "gold" or c_loyalty_tier == "silver" %}
    Adult loyalty member content.
  {% else %}
    Adult non-member content.
  {% endif %}
{% else %}
  This offer is for adults only.
{% endif %}
```

## Custom attributes in conditions

Reference custom attributes in conditions with **c_** prefix.

```plaintext
{% if c_preferred_store != blank %}
  Your nearest store: {{ c_preferred_store }}
{% endif %}

{% if c_membership_date != blank %}
  Member since: {{ c_membership_date | time_format: "MMMM YYYY" }}
{% endif %}
```