I'm new to Rails. When I'm studying Rails, I come across some methods which I don't know how to use.
Then I try to Google, but the outcome is not very good.
For example, I defined a model
To see where specific method is defined, you can check it as follows:
@users.method(:present?) #=> #<Method: User(Object)#present?>
This means, that method
present? is defined in class
In your case, here is documentation for