Difference Between Array and ArrayList in Java

Difference Between Array and ArrayList in Java

Code Examples

Array Example

int[] numbers = new int[3]; // Fixed size
numbers[0] = 10;
numbers[1] = 20;
numbers[2] = 30;

for (int number : numbers) {
    System.out.println(number);
}

ArrayList Example

import java.util.ArrayList;

ArrayList<Integer> numbers = new ArrayList<>(); // Dynamic size
numbers.add(10); // Adding elements
numbers.add(20);
numbers.add(30);
numbers.remove(1); // Removing the element at index 1

for (int number : numbers) {
    System.out.println(number);
}

Key Takeaway

• Use Array when the number of elements is fixed and performance is a priority.
• Use ArrayList when flexibility and ease of use (like resizing and built-in methods) are needed.