LinkedList indexOf() method in Java

The Java.util.LinkedList.indexOf(Object element) method is used to check and find the occurrence of a particular element in the list. If the element is present then the index of the first occurrence of the element is returned otherwise -1 is returned if the list does not contain the element.

Syntax:

LinkedList.indexOf(Object element)

Parameters: The parameter element is of the type LinkedList. It specifies the element whose occurrence is needed to be checked in the LinkedList.

Return Value: The method returns the index or position of the first occurrence of the element in the list else -1 if the element is not present in the list. The returned value is of integer type.

Below program illustrate the Java.util.LinkedList.indexOf() method:

// Java code to illustrate indexOf()
import java.io.*;
import java.util.LinkedList;

public class LinkedListDemo {
   public static void main(String args[]) {

      // Creating an empty LinkedList
      LinkedList<String> list = new LinkedList<String>();

      // Use add() method to add elements in the list
      list.add("Geeks");
      list.add("for");
      list.add("Geeks");
      list.add("10");
      list.add("20");

      // Displaying the list
      System.out.println("LinkedList:" + list);

      // The first position of an element
      // is returned
      System.out.println("The first occurrence of Geeks is at index:"
                                              + list.indexOf("Geeks"));
      System.out.println("The first occurrence of 10 is at index: "
                                               + list.indexOf("10"));

   }
}

Output:

LinkedList:[Geeks, for, Geeks, 10, 20]
The first occurrence of Geeks is at index: 0
The first occurrence of 10 is at index: 3