What is it? to groovy variables?

Question

I saw in some groovy code:

trip.id?.encodeAsHTML()

What is the difference between using or not having "id ?."?

Answer 1

It checks if the object is null or not. Using this, you can throw a nullpointer exception.

If you use it, you should use it for the entire object (for example: trip.id?.otherstuff?morestuff?.encodeAsHTML ()

Answer 2

He called the "null-safe dereference operator." The difference is that if trip.idit is null, instead of throwing NullPointerException, it returns nullas a result of calling the method.

Answer 3

Groovy . . Groovy .