A Linked List of Objects Solution

A Linked List of Objects

The file IntList.java contains an example of a linked list of integers A list of objects is a lot like a list of integers or a particular type of object such as a Magazine, except the value stored is an Object, not an int or Magazine.

// ***************************************************************

// FILE: IntList.java

//

// Purpose: Defines a class that represents a list of integers

//

// ***************************************************************

public class IntList

{

privateIntNode front; //first node in list

//-----------------------------------------

// Constructor. Initially list is empty.

//-----------------------------------------

publicIntList()

{

front = null;

}

//-----------------------------------------

// Adds given integer to front of list.

//-----------------------------------------

public void addToFront(intval)

{

front = new IntNode(val,front);

}

//-----------------------------------------

// Adds given integer to end of list.

//-----------------------------------------

public void addToEnd(intval)

{

IntNodenewnode = new IntNode(val,null);

//if list is empty, this will be the only node in it

if (front == null)

front = newnode;

else

{

//make temp point to last thing in list

IntNode temp = front;

while (temp.next != null)

temp = temp.next;

//link new node into list

temp.next = newnode;

}

}

//-----------------------------------------

// Removes the first node from the list.

// If the list is empty, does nothing.

//-----------------------------------------

public void removeFirst()

{

if (front != null)

front = front.next;

}

//------------------------------------------------

// Prints the list elements from first to last.

//------------------------------------------------

public void print()

{

System.out.println("--------------------");

System.out.print("List elements: ");

IntNode temp = front;

while (temp != null)

{

System.out.print(temp.val + " ");

temp = temp.next;

}

System.out.println("\n-----------------------\n");

}

//*************************************************************

// An inner class that represents a node in the integer list.

// The public variables are accessed by the IntList class.

//*************************************************************

private class IntNode

{

publicintval; //value stored in node

publicIntNode next; //link to next node in list

//------------------------------------------------------------------

// Constructor; sets up the node given a value and IntNode reference

//------------------------------------------------------------------

publicIntNode(intval, IntNode next)

{

this.val = val;

this.next = next;

}

}

}

Write a class ObjList that contains arbitrary objects and that has the following methods: