target == p.getValue() 

More Boundries

Here is the program, again:

import java.util.* ;

public class LinearSearch
{
  public static void main ( String[] args )
  {
    
    // Build a linked list
    Node node0 = new Node(  2 );    
    Node node1 = new Node(  3 ); node0.setNext( node1 );
    Node node2 = new Node(  5 ); node1.setNext( node2 );
      
    // Ask the user for a target
    Scanner scan = new Scanner( System.in );
    System.out.println("Number to search for: ");
    int target = scan.nextInt();
          
    // Traverse the Linked List in a loop.
    // Stop when the target is found.  
    Node p = node0;
    boolean found = false;
    
    while (  p != null  && !found )
    {
      if ( target == p.getValue() ) 
        found = true;
      else
        p = p.getNext();
    }
    
    // Display the results
    if ( found )
      System.out.println( target + " is in the list." );
    else
      System.out.println( target + " is NOT in the list." );
  }
}

There are many things to get correct. The traversal must

• visit the first node,
• exit correctly if the target is there,
• visit the last node if the target has not been found
• correctly report if the target is there or not,
• not go beyond the end of the list,
• work with an empty list,
• correctly reports that the target is not in the list,
• work with a list of one node, and
• work with a list of many nodes.