Java – Search elements in LinkedList example

In this tutorial we will learn how to search elements in LinkedList. We will be using following two methods for searching elements.

public int indexOf(Object o): Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.

public int lastIndexOf(Object o): Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.

Example

Here we are having a LinkedList of String elements and we are searching a string using indexOf() and lastIndexOf() methods of LinkedList class.

import java.util.LinkedList;
public class SearchInLinkedList {
 
  public static void main(String[] args) {
 
     // Step1: Create a LinkedList
     LinkedList<String> linkedlist = new LinkedList<String>();
 
     // Step2: Add elements to LinkedList
     linkedlist.add("Tim");
     linkedlist.add("Rock");
     linkedlist.add("Hulk");
     linkedlist.add("Rock");
     linkedlist.add("James");
     linkedlist.add("Rock");
 
     //Searching first occurrence of element
     int firstIndex = linkedlist.indexOf("Rock");
     System.out.println("First Occurrence: " + firstIndex);
 
     //Searching last occurrence of element
     int lastIndex = linkedlist.lastIndexOf("Rock");
     System.out.println("Last Occurrence: " + lastIndex);
  }
}

Output:

First Occurrence: 1
Last Occurrence: 5

Reference:
LinkedList JavaDoc