Java Articles

ArrayList vs LinkedList in Java — Performance and When to Use Each

ArrayList offers fast random access backed by an array; LinkedList offers fast insertion/removal at the ends backed by nodes. Learn the real tradeoffs.

Interface vs Abstract Class in Java — When to Use Each

An interface defines a contract any class can implement; an abstract class provides shared state and partial implementation for related subclasses.

Checked vs Unchecked Exceptions in Java

Checked exceptions must be declared or caught at compile time; unchecked exceptions (RuntimeException) don't require handling. Learn when to use each.

equals() and hashCode() in Java — Why You Must Override Both

Overriding equals() without hashCode() breaks HashMap and HashSet behavior. Learn the contract between them and why they must be consistent.

String vs StringBuilder in Java — Which Should You Use?

Java Strings are immutable, so repeated concatenation creates many objects; StringBuilder mutates a buffer in place for far better performance in loops.