Mastering Java Collections: An In-Depth Guide for Developers

Java Collections Framework provides essential data structures like Lists, Sets, and Maps. Each collection type is suited for different use cases. For example, a List stores ordered elements, while a Set stores unique elements.

One of the most commonly used collections is ArrayList, which allows dynamic resizing. Here’s how you can use an ArrayList in Java:

import java.util.ArrayList;
public class Example {
    public static void main(String[] args) {
        ArrayList list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");
        System.out.println(list.get(0)); // Output: Apple
    }
}
            

Java also provides HashMap, which is used for storing key-value pairs. It is efficient for quick lookups. Collections like TreeSet and TreeMap are used when sorted elements are needed. Understanding the right data structure helps improve performance and code efficiency.