Java Reference
In-Depth Information
}
}
Directory "TryParameterizedMethods"
The output should be as follows:
Ann
Manager Freda level: 3
Manager Jane level: 1
Manager Joe level: 3
Mary
Stan
Tina
Will
How It Works
You create an object of a
BinaryTree
type that stores
Person
objects:
BinaryTree<Person> people = new BinaryTree<>();
You then define an array of
Manager
objects and add those to the
people
binary tree:
Manager[] managers = { new Manager("Jane",1), new
Manager("Joe",3),
new
Manager("Freda",3)};
for(Manager manager : managers){
people.add(manager);
}
The
add()
method is defined as a parameterized method in the
BinaryTree<>
type definition, where
the method's parameter,
E
, has an upper bound that is the type variable for the
BinaryTree<>
type. This
enables the
add()
method to accept arguments that are of a type that can be type
Person
or any subclass
of
Person
. You defined the
Manager
class with
Person
as the base class so the
add()
method happily
accepts arguments of type
Manager
.
Just to demonstrate that you can, you create an array of
Person
objects and add those to the
people
bin-
ary tree:
Person[] persons = {
new Person("Will"), new Person("Ann"), new
Person("Mary"),
new Person("Tina"), new Person("Stan")};
for(Person person : persons) {
people.add(person);
}
You now have a mix of
Person
and
Manager
objects in the binary tree. You list the contents of the binary
tree in ascending alphabetical order by calling the parameterized
listAll()
method that you defined as
a static member of the
TryParameterizedMethods
class:
