If you work with Twig, you already know: templates should be clean, fast,
and free of unnecessary PHP code. Ternary operators are the tool that lets
you replace bulky {% if %} blocks with a single compact line
and save dozens of lines in your templates.
Twig is used in many popular systems:
- Symfony
- Drupal 8+ / 10+
- OpenCart 3.0+ and 4.x
- Craft CMS
- Bolt CMS, Grav, and many other PHP projects
This cheat sheet is especially useful for
OpenCart developers. In this CMS, almost all templates
(product.twig, category.twig, cart.twig, etc.) are built with Twig, and the
ability to write short conditional expressions greatly simplifies theme
customization, module development, and project maintenance.
Support for extended ternary operators was added back in
Twig 1.12.0. Since then, they have become a must-have for
any Twig developer.
1. Classic Ternary Operator (if — else)
{{ foo ? 'yes' : 'no' }}
2. Elvis Operator — “if it exists, output it, otherwise default”
{{ foo ?: 'no' }}
Or the full equivalent:
{{ foo ? foo : 'no' }}
3. One-sided Ternary Operator (true part only)
{{ foo ? 'yes' }}
Or explicitly:
{{ foo ? 'yes' : '' }}
4. Null Coalescing Operator ?? (since Twig 2.7.0+, for the new OpenCart releases only)
{{ foo ?? 'no' }}
Important: Returns foo only if the variable is
defined and is not null. Empty values
('', 0, false, empty array) are
considered valid and are not replaced.
5. default Filter — The Most Flexible Option
{{ foo|default('no') }}
Difference from ??:
-
|default replaces the value if the variable is
undefined or
empty (false, 0,
'', null, []).
-
?? replaces only null or an undefined
variable.
In OpenCart practice, |default is used more often because many
variables can be empty strings or zeros.
Comparison Table
|
Operator
|
Replaces null/undefined
|
Replaces empty values ('' , 0 , false)
|
foo ? 'yes' : 'no' |
Yes
|
Yes
|
foo ?: 'no' |
Yes
|
Yes
|
foo ? 'yes' |
Yes
|
Yes
|
foo ?? 'no' |
Yes
|
No
|
foo|default('no') |
Yes
|
Yes
|
Practical Examples for OpenCart
<!-- Product price -->
<span class="price">{{ product.special ?? product.price|default('On request') }}</span>
<!-- Stock status -->
{{ product.quantity > 0 ? 'In stock' : 'Pre-order' }}
<!-- Sale badge class -->
<div class="{{ product.special ? 'product--sale' : '' }}">
Useful Tips
-
Don’t overuse nested ternary operators — the code becomes hard to read.
-
For complex conditions, it’s better to use
{% if %} blocks
or a separate macro.
- In Twig 3.x+, ternary operators work even more reliably with types.
-
If you’re using OpenCart 4.x — Twig is updated there, so all the
constructions above work without issues.
Bookmark this article — you’ll definitely need it the next time you refactor
a template or create a new module.
