attribute
is a Twig function that can be used to access a "dynamic" attribute of a variable:
{{ attribute(object, method) }}
{{ attribute(object, method, arguments) }}
{{ attribute(array, item) }}
In addition, the defined test can check for the existence of a dynamic attribute:
{{ attribute(object, method) is defined ? 'Method exists' : 'Method does not exist' }}
The resolution algorithm is the same as the one used for the . notation, except that the item can be any valid expression.
Source: Twig