Java NullPointerException while accessing ArrayList element

Hi everyone,
I am a beginner learning Java and I’m facing an issue with an ArrayList.
I am getting a NullPointerException when trying to print elements.
What I am trying to do
Store student names in an ArrayList and print them using a loop.
Problem
The program compiles successfully but throws an exception at runtime.
My Code
Copy code
Java
import java.util.*; public class StudentList {    public static void main(String[] args) {        ArrayList<String> names = null;        names.add("Ravi");        names.add("Kumar");        for(String name : names){            System.out.println(name);        }    } }

What did you assign the ArrayList reference to?

Don't declare it as ArrayList<String>, but as List<String>. That allows you to use different types of List.

On line 6 you assign null to names so when you try to access names on line 8 you get an exception.

names is null, it does not point to any object.  
you are trying to call a method on a null reference, which causes the exception at runtime.
Initialize the list properly
List<String> names = new ArrayList<>();
Now names refers to an actual object, so add() and the loop will work correctly.