Usage and examples of Java ArrayList removeRange()

Java ArrayList Methods

The Java ArrayList removeRange() method deletes elements from the ArrayList between specified indices.

The syntax of removeRange() method is:

arraylist.removeRange(int fromIndex, int toIndex)

removeRange() parameters

removeRange() method has two parameters.

• fromIndex -The starting position of the element to be deleted from

• toIndex - The end position of the element to be deleted

The return value of removeRange()

The removeRange() method does not return any value. Instead, it deletes a part of the arraylist

A part of arraylist starting from fromIndex includes elements up to toIndex-1of the elements. That is, it does not include the element at toIndex

Note: If fromIndex or toIndex is out of range, or toIndex < fromIndex, the method throws an IndexOutOfBoundsException.

Example1: Java ArrayList removeRange()

import java.util.*;
class Main extends ArrayList<String> {
　　　　public static void main(String[] args) {
　　　　　　　　//Create an ArrayList
　　　　　　　　Main arraylist = new Main();
　　　　　　　　//Add elements to the ArrayList
　　　　　　　　arraylist.add("Java");
　　　　　　　　arraylist.add("English");
　　　　　　　　arraylist.add("Spanish");
　　　　　　　　arraylist.add("Python");
　　　　　　　　arraylist.add("JavaScript");
　　　　　　　　System.out.println("ArrayList: ")　+　arraylist);
　　　　　　　　//delete1to3between elements
　　　　　　　　arraylist.removeRange(1,　3);
　　　　　　　　System.out.println("Updated ArrayList: ")　+　arraylist);
　　　　}
}

Output Result

ArrayList: [Java, English, Spanish, Python, JavaScript]
Updated ArrayList: [Java, Python, JavaScript]

The removeRange() method uses the access modifier protected. This means it can only beclass / package / subclass (subclass)Access it. This is why the Main method in the above example inherits the ArrayList class.

Since the Main class inherits all properties of ArrayList, we can use the Main class to create an arraylist.

However, this is not commonly used in Java. Instead, we useArrayList subList()andArrayList clear()Method.

Example2: Delete multiple elements

import java.util.ArrayList;
class Main {
　　　　public static void main(String[] args) {
　　　　　　　　//Create an ArrayList
　　　　　　　　ArrayList<Integer> numbers = new ArrayList<>();
　　　　　　　　//Add elements to the ArrayList
　　　　　　　　numbers.add(1);
　　　　　　　　numbers.add(2);
　　　　　　　　numbers.add(3);
　　　　　　　　numbers.add(4);
　　　　　　　　numbers.add(6);
　　　　　　　　System.out.println("ArrayList: ")　+　numbers);
　　　　　　　　//delete1to3between elements
　　　　　　　　numbers.subList(1,　3).clear();
　　　　　　　　System.out.println("Updated ArrayList: ")　+　numbers);
　　　　}
}

Output Result

ArrayList: [1,　2,　3,　4,　6]
Updated ArrayList: [1,　4,　6]

In the above example, we created an array list named numbers. Note this line,

numbers.subList(1,　3).clear();

Here,

• subList(1, 3) - return index1and2ofelements

• clear() -　 Delete elements returned by subList()
  

Java ArrayList Methods