Try to work with the helping elements before looking at the solution…

Helping elements

• to be available in Tree and in SpatializedTree, the new variables should be added in the superclass: Tree: they will be inherited in the subclass.

• the three getters should be added in the same class, getId ()…

• you may adapt the constructor of Tree to get the 3 extra parameters and store them in the 3 new instance variables like for dbh

• the toString () method of Tree may be adapted to display the 4 instance variables

• the toString () method of SpatializedTree relying on its superclass needs no change

• the code of exercice 1. needs adaptation to match the new constructor of Tree with its 4 parameters

A possible solution