1. Introduction

In Java, the ArrayList class provides a method called subList(int fromIndex, int toIndex) which is used to obtain a portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive. In this blog post, we will learn how to use the subList method to extract a sublist from an ArrayList.

2. Program Steps

1. Create an ArrayList and add some elements to it.

2. Print the original ArrayList.

3. Use the subList() method to extract a sublist from the ArrayList.

4. Print the extracted sublist.

3. Code Program

import java.util.ArrayList;
import java.util.List;

public class ArrayListSubList {

    public static void main(String[] args) {

        // Step 1: Create an ArrayList and add some elements to it
        ArrayList<String> animals = new ArrayList<>();
        animals.add("Cat");
        animals.add("Dog");
        animals.add("Elephant");
        animals.add("Fox");
        animals.add("Giraffe");

        // Step 2: Print the original ArrayList
        System.out.println("Original ArrayList: " + animals);

        // Step 3: Use subList() method to extract a sublist from the ArrayList
        List<String> subList = animals.subList(1, 4);

        // Step 4: Print the extracted sublist
        System.out.println("SubList extracted from ArrayList: " + subList);
    }
}

Output:

Original ArrayList: [Cat, Dog, Elephant, Fox, Giraffe]
SubList extracted from ArrayList: [Dog, Elephant, Fox]

4. Step By Step Explanation

Step 1: We initialize an ArrayList named animals and populate it with the elements "Cat", "Dog", "Elephant", "Fox", and "Giraffe".

Step 2: The original ArrayList is printed to the console.

Step 3: We use the subList() method to extract a sublist from the ArrayList. The subList method takes two parameters, the fromIndex and the toIndex. In this example, we extract the sublist from index 1 (inclusive) to index 4 (exclusive).

Step 4: The extracted sublist is printed to the console, showing the elements "Dog", "Elephant", and "Fox".