Linked List Objective: The purpose of this exercise is to create a Linked List data structure that mimics the behavior of the Java Standard Library Version (Java API). The outcomes/results of using the library features should be identical with your own version (My API). However, the underlying implementation should follow with the descriptions listed below. Instructions : Create the following Linked List Data Structure with the given description below in your utils package and use "for loops" for your repetitive tasks. Where to find starter code in my-api package.class : utils.LinkedList package.class : tests.console.week04.LinkedListTest Where to find your JUNIT test in my-api package.class : tests.junit.LinkedListJUnitTest Nested Class that has to be added to LinkedList class package.class : utils.LinkedList.Node Task Check List ONLY "for" loops should be used within the data structure class. There is an automatic 30% deduction, if other loops are used. The names of identifiers MUST match the names listed in the description below. Deductions otherwise. Complete coding Assignment in your "my-api" GitHub Repository. You will not be graded otherwise and will receive a 0, if not uploaded there. Run JUNIT TEST and take a SNAPSHOT of results. Upload PDF of snapshot of your JUnitTest results to Canvas. Description The internal structure of the Linked List is a doubly linked Node data structure and should have at a minimum the following specifications: data fields: The data fields to declare are private and you will keep track of the size of the list with the variable size and the start of the list with the reference variable data. first is a reference variable for the first Node<E> in the list. last is a reference variable for the last Node<E> in the list. size keeps track of the number of nodes in the list of type int. This will allow you to know the current size of the list without having to traversing the list. constructors: The overloaded constructors will initialize the data fields size and data. A constructor that is a default constructor initializes the starting node location first and size to a zero equivalent, that is, constructs an empty list. methods: methods that manages the behavior of the linked nodes. Together, the methods below give the illusion of a index or countable location. Implement these methods within your generic Linked List class. Method Description Header public boolean add(E item) public void add(int index, E item) public void append( E item) private void checkIndex(int index) public boolean contains(E item) public void clear() private E detach(int index) public E get(int index) public int indexOf(E item) private void insertBefore(int index, E item) public boolean isEmpty() private Node<E> node(int index) public E remove(int index) public boolean remove(E item) public E set(int index, E item) public int size() public String toString() Node Data Structure The generic Linked List class includes a static Node class as a ne.

1. Linked List
Objective: The purpose of this exercise is to create a Linked List data structure that mimics the
behavior of the Java Standard Library Version (Java API). The outcomes/results of using the
library features should be identical with your own version (My API). However, the underlying
implementation should follow with the descriptions listed below.
Instructions : Create the following Linked List Data Structure with the given description below in
your utils package and use "for loops" for your repetitive tasks.
Where to find starter code in my-api
package.class : utils.LinkedList
package.class : tests.console.week04.LinkedListTest
Where to find your JUNIT test in my-api
package.class : tests.junit.LinkedListJUnitTest
Nested Class that has to be added to LinkedList class
package.class : utils.LinkedList.Node
Task Check List
ONLY "for" loops should be used within the data structure class. There is an automatic 30%
deduction, if other loops are used.
The names of identifiers MUST match the names listed in the description below. Deductions
otherwise.
Complete coding Assignment in your "my-api" GitHub Repository. You will not be graded
otherwise and will receive a 0, if not uploaded there.
Run JUNIT TEST and take a SNAPSHOT of results. Upload PDF of snapshot of your JUnitTest
results to Canvas.
Description
The internal structure of the Linked List is a doubly linked Node data structure and should have
at a minimum the following specifications:
data fields: The data fields to declare are private and you will keep track of the size of the list with
the variable size and the start of the list with the reference variable data.
first is a reference variable for the first Node<E> in the list.
last is a reference variable for the last Node<E> in the list.
size keeps track of the number of nodes in the list of type int. This will allow you to know the
current size of the list without having to traversing the list.
constructors: The overloaded constructors will initialize the data fields size and data.
A constructor that is a default constructor initializes the starting node location first and size to a
zero equivalent, that is, constructs an empty list.
methods: methods that manages the behavior of the linked nodes.
Together, the methods below give the illusion of a index or countable location. Implement these
methods within your generic Linked List class.
Method
Description
Header
public boolean add(E item)

2. public void add(int index, E item)
public void append( E item)
private void checkIndex(int index)
public boolean contains(E item)
public void clear()
private E detach(int index)
public E get(int index)
public int indexOf(E item)
private void insertBefore(int index, E item)
public boolean isEmpty()
private Node<E> node(int index)
public E remove(int index)
public boolean remove(E item)
public E set(int index, E item)
public int size()
public String toString()
Node Data Structure
The generic Linked List class includes a static Node class as a nested class, i.e. a static inner
class within the Linked List class.
inner class: class inside the body of another class.
Note: This private class does not require access to instance members of the outer class, so it is
declared static. This means that the node object wont be coupled to the outer class object, thus
will be more optimal since it wont require heap/stack memory.
data fields:
data : hold the data stored in each node as is of type E.
next : stores the location of the next node in the list.
prev : stores the location of the previous node in the list.
constructor:
A constructor that receives parameters for data, and prev and calls the second constructor.
public Node(Node<E> prev, E data)
A constructor that receives parameters for data, next and prev.
public Node(Node<E> prev, E data, Node<E> next)
Method Description Header
add(item)
uses the append method and
ensures that there is enough
spaces to store each element in
the list. Also updates the
number of elements in the list
by one. This method returns
true, if the data was added
successfully.
public boolean add(E item)

3. add(index, item)
inserts elements at a given
location in the list, shifting
subsequent elements to the
right. Uses the append and
insertBefore methods to assist
with adding items to the front,
back and middle of the list.
Updates the number of
elements in the list by one.
public void add(int index, E
item)
append(item)
appends elements to the end of
the list, but does not update the
number of elements. This is a
private helper method.
public void append( E item)
checkIndex(index)
checks if the given index is
valid. Validation means that you
cannot access indexes where
elements have not been placed.
Throws an
IndexOutOfBoundsException
, if invalid. This is a private
helper method.
private void checkIndex(int
index)
contains(item)
searches for a specific item
within the linked structure and
returns true, if the item is in the
list.
public boolean contains(E
item)
clear()
clears list of all elements,
returns size back to zero.
public void clear()
detach(index)
detaches the node at the
specified index from list and
returns the deleted element, but
does not reduce the size of the
list. This is a private helper
method.
private E detach(int index)
get(index)
returns the item at the specified
position in the list. This method
first checks if the index
requested is valid.
public E get(int index)

4. indexOf(item)
searches for a specific item
within the linked structure and
returns the first occurrence (i.e.
index location) in the list,
otherwise returns -1, if NOT
found.
public int indexOf(E item)
insertBefore(index, item)
inserts an item before the non-
null node at the specified index
in the list. Traverses the list to
find this node. This method also
checks for insertions at the start
and end of the list, as well as
when empty. This is a private
helper method.
private void insertBefore(int
index, E item)
isEmpty()
returns true, if the list is empty,
i.e., the list contains no
elements.
public boolean isEmpty()
node(index)
returns a reference to the node
at the given position in the list.
This node traverses the list in
two directions from front to
middle and back to middle. This
is a private helper method.
private Node<E> node(int
index)
remove(index)
removes the item at the given
position in the list for a valid
index. Checks for valid index
before it proceeds with removal.
Shifts subsequent elements to
the left and returns the item
removed. The number of
elements in the list is reduced
by one.
public E remove(int index)
remove(item)
removes the first occurrence of
the specified item from the list,
if present. Shifts subsequent
elements to the left and returns
true, if the item is removed. The
number of elements in the list is
reduced by one.
public boolean remove(E item)

5. set(index, item)
replaces the item at the
specified position with the one
passed. This method checks if
the index requested is valid
before it does the replacement
and returns the replaced item.
public E set(int index, E item)
size()
returns the number of elements
in the list.
public int size()
toString()
displays the contents of the list
according to the same format at
shown in the Java API.
public String toString()