Difference Between Array and ArrayList in Java

 Both Array and ArrayList are used to store multiple values in Java — but they work a little differently.

Let’s look at what makes them different, and when to use each one.

Array

• Fixed size (you can’t change it once created)

• Can store primitive types like int, double, etc.

• Syntax:
  

  int[] numbers = new int[5];

  numbers[0] = 10;
  
  
  ArrayList
  

• Can grow and shrink in size

• Only works with objects, not primitives (use Integer instead of int)

• Comes from java.util.ArrayList

• Syntax:
  

  import java.util.ArrayList;

  ArrayList<Integer> numbers = new ArrayList<>();

  numbers.add(10);