Search for items in LinkedList in Java

In this tutorial, we'll look at ways to  find an item in a LinkedList using the following two methods:

public indexOf(Object o): returns the index of the first occurrence of the specific object, otherwise -1 if the list does not contain this element.

public int lastIndexOf(Object o):   returns the index of the last occurrence of the specific object, otherwise -1 if the list does not contain that element.

Example:

Here is a LinkedList that contains String elements. We use indexOf() and lastIndexOf() to look for a String:

import java.util.LinkedList; 

public class Search {
 
 public static void main(String[] args) {
 
 // create an instance of LinkedList
 LinkedList linkedlist = new LinkedList(); 
 
 // insert elements
 linkedlist.add("abc"); 
 linkedlist.add("abcd"); 
 linkedlist.add("bc"); 
 linkedlist.add("def"); 
 linkedlist.add("abcd"); 
 linkedlist.add("ijk"); 
 linkedlist.add("ghi"); 
 
 //find the first occurrence encountered
 int procc = linkedlist.indexOf("abcd"); 
 System.out.println("First occurrence: " + procc); 
 
 //find the last occurrence encountered
 int drocc = linkedlist.lastIndexOf("abcd"); 
 System.out.println("Last Occurrence: " + drocc); 
 }
}

Output:

First Occurrence: 1
Last Occurrence: 4