IndexOf Method of AbstractSequentialList in Java

The indexOf() method is inherited from the AbstractList class. It is used to return the index of the first occurrence of the specified element in this list. If the list is empty, it returns -1.

The syntax is as follows −

public int indexOf(Object ele)

Here, ele is the element for which you want the index.

To work with the AbstractSequentialList class in Java, you need to import the following package −

import java.util.AbstractSequentialList;

The following is an example to implement AbstractSequentialList indexOf() method in Java −

Example

 Live Demo

import java.util.LinkedList;
import java.util.AbstractSequentialList;

public class Demo {
   public static void main(String[] args) {
      AbstractSequentialList<Integer> absSequential = new LinkedList<>();
      absSequential.add(110);
      absSequential.add(320);
      absSequential.add(400);
      absSequential.add(550);
      absSequential.add(600);
      absSequential.add(700);
      absSequential.add(900);
      System.out.println("Elements in the AbstractSequentialList = "+absSequential);
      System.out.println("Elements in the AbstractSequentialList = "+absSequential.indexOf(550));
   }
}

Output

Elements in the AbstractSequentialList = [110, 320, 400, 550, 600, 700, 900]
Elements in the AbstractSequentialList = 3

Let us see another example wherein the element does not exist −

Example

 Live Demo

import java.util.LinkedList;
import java.util.AbstractSequentialList;

public class Demo {
   public static void main(String[] args) {
      AbstractSequentialList<Integer> absSequential = new LinkedList<>();
      absSequential.add(110);
      absSequential.add(320);
      absSequential.add(400);
      absSequential.add(550);
      absSequential.add(600);
      absSequential.add(700);
      absSequential.add(900);
      System.out.println("Elements in the AbstractSequentialList = "+absSequential);
      System.out.println("Elements in the AbstractSequentialList = "+absSequential.indexOf(10));
   }
}

Output

Elements in the AbstractSequentialList = [110, 320, 400, 550, 600, 700, 900]
Elements in the AbstractSequentialList = -1