Groovy: What happens if the safe navigation operator returns null on a primitive assignment?

Question

Character parrot = null
int hp = parrot?.hp
if (hp < 0) {
    print (parrot+" is pining for the fjords.")
}

Essentially, what happens in the second line? Is hp set to null, even though it's a primitive? Do we get an exception? Or is it, for some reason, set to 0?

(Research indicates that (null < 0) == true, so that part is fine.)

Also, do things change if we instead write:

Character parrot = null
if (parrot?.hp < 0) {
    print (parrot+" is pining for the fjords.")
}

Answer 1

1. you get:

   org.codehaus.groovy.runtime.typehandling.GroovyCastException:
        Cannot cast object 'null' with class 'null' to class 'int'.
        Try 'java.lang.Integer' instead
   

2. Yes. As you say, null < 0 so you get the output:

   null is pining for the fjords