Find SubList of ArrayList

by Shekhar Sharma · September 17, 2015

In the previous post, we have seen how to sort the arrayList by using comparable and comparator.In this post, we will see how to get a sublist from a ArrayList.

Find SubList of ArrayList:

We have method called ‘sublist’ where we can define the range of sublist which needs to be acquired.

Syntax:

List subList(int fromIndex, int toIndex)

fromIndex: Start position of the range

toindex: End position of the range

Sublist method returns a type of list, so to store a list into arraylist we need to type cast the returned value. If list gets stored in the List directly , then there is no need to typecast.

It will be more clear with the below example.

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

public class ArrayListEx {

	public static void main(String[] args) {
		ArrayList<String> fruits = new ArrayList<String>();
		fruits.add("Orange");
		fruits.add("Mango");
		fruits.add("Apple");
		fruits.add("Grapes");
		fruits.add("Banana");
		System.out.println("List of total fruits: "+fruits);

		ArrayList<String> sub1 = new ArrayList<String>(fruits.subList(2, 4));
		System.out.println("SubList of fruits stored in arrayList : "+sub1);
		
		List<String> sub2 =  fruits.subList(2, 4);
		System.out.println("SubList of fruits stored in List directly : "+sub2);
	}
}

Output:

List of total fruits: [Orange, Mango, Apple, Grapes, Banana] SubList of fruits stored in arrayList : [Apple, Grapes] SubList of fruits stored in List directly : [Apple, Grapes]

Note:
The subList method throws IndexOutOfBoundsException – if the specified indexes are out of the range of ArrayList (fromIndex < 0 || toIndex > size).
IllegalArgumentException – if the starting index is greater than the end point index (fromIndex > toIndex).

Find SubList of ArrayList