Chapter 19, Problem 2FTE

Explanation of Solution

Purpose of the given code:

The given code is used to displays all the elements in a list “myList”.

Given code:

/* Set a reference "ref" to the first node in the list "myList" */

Node ref = myList; //Line 1

/* This loop will perform up to the reference "ref" is equal to "null" */

while (ref.next != null) //Line 2

{

    /* Display the first node in the "ref" */

    System.out.print(ref.value + " "); //Line 3

/* Move on to the next node by assigning "ref" to the successor of the existing node */

    ref = ref.next; //Line 4

}

Error in the given code:

• The error is present in “line 2”, in the “while” loop.
  • This error causes a “NullPointerException” if the list is empty and also the code will fail to display the last value in a nonempty list.
• Therefore, user should replace “ref != null” in the place of “ref.next != null”...