# Operators

## Comparisons

The following comparison operators are supported in any expression: ==, !=, <, >, >=, and <=.

You can also check if a string starts with or ends with another string:

``````{% if 'Fabien' starts with 'F' %}
{% endif %}

{% if 'Fabien' ends with 'n' %}
{% endif %}
``````

## Logic

You can combine multiple expressions with the following operators:

• and: Returns true if the left and the right operands are both true.
• or: Returns true if the left or the right operand is true.
• not: Negates a statement.
• (expr): Groups an expression.

## Math

Twig allows you to calculate with values. This is rarely useful in templates but exists for completeness' sake. The following operators are supported:

• +: Adds two objects together (the operands are casted to numbers). {{ 1 + 1 }} is 2.
• -: Subtracts the second number from the first one. {{ 3 - 2 }} is 1.
• /: Divides two numbers. The returned value will be a floating point number. {{ 1 / 2 }} is {{ 0.5 }}.
• %: Calculates the remainder of an integer division. {{ 11 % 7 }} is 4.
• //: Divides two numbers and returns the floored integer result. {{ 20 // 7 }} is 2, {{ -20 // 7 }} is -3 (this is just syntactic sugar for the round filter).
• : Multiplies the left operand with the right one. {{ 2 2 }} would return 4.
• : Raises the left operand to the power of the right operand. {{ 2 3 }} would return 8.

## Is

The is operator performs tests. Tests can be used to test a variable against a common expression. The right operand is name of the test:

``````{# find out if a variable is odd #}

{{ name is odd }}
``````

Tests can accept arguments too:

``````{% if post.status is constant('Post::PUBLISHED') %}
``````

Tests can be negated by using the is not operator:

``````{% if post.status is not constant('Post::PUBLISHED') %}

{# is equivalent to #}
{% if not (post.status is constant('Post::PUBLISHED')) %}
``````

## In

The in operator performs containment test.

It returns true if the left operand is contained in the right:

``````{# returns true #}

{{ 1 in [1, 2, 3] }}

{{ 'cd' in 'abcde' }}
``````

To perform a negative test, use the not in operator:

``````{% if 1 not in [1, 2, 3] %}

{# is equivalent to #}
{% if not (1 in [1, 2, 3]) %}
``````

## Other

• The following operators don't fit into any of the other categories:
• |: Applies a filter.
• ..: Creates a sequence based on the operand before and after the operator
``````{{ 1..5 }}

{# equivalent to #}
{{ range(1, 5) }}
``````
• Note that you must use parentheses when combining it with the filter operator due to the operator precedence rules:
``````(1..5)|join(', ')
``````
• ~: Converts all operands into strings and concatenates them. {{ "Hello " ~ name ~ "!" }} would return (assuming name is 'John')Hello John!.
• ., []: Gets an attribute of an object.
• ?:: The ternary operator:
``````{{ foo ? 'yes' : 'no' }}

{# as of Twig 1.12.0 #}
{{ foo ?: 'no' }} is the same as {{ foo ? foo : 'no' }}
{{ foo ? 'yes' }} is the same as {{ foo ? 'yes' : '' }}
``````
• ??: The null-coalescing operator:
``````{# returns the value of foo if it is defined and not null, 'no' otherwise #}
{{ foo ?? 'no' }}
``````