Lambda Expressions
Learn what lambda expressions are in Java 8, their syntax, and how they replace anonymous classes for cleaner code.
Functional Interfaces
Understand Java's built-in functional interfaces — Predicate, Function, Consumer, Supplier, BiFunction — and how to create your own.
Stream API
Master Java 8 Stream API — learn to create streams, use filter/map/sorted and collect/reduce terminal operations with real examples.
Optional Class
Learn how Java's Optional class eliminates NullPointerException by wrapping nullable values safely with orElse, map, and filter.
Default and Static Interface Methods
Learn how Java 8 added default and static methods to interfaces for backward compatibility, with conflict resolution and real examples.
Method References
Learn the 4 types of Java method references — static, instance, arbitrary instance, and constructor — as cleaner shorthand for lambdas.
Date and Time API
Master Java 8's new Date-Time API with LocalDate, LocalDateTime, ZonedDateTime, DateTimeFormatter, Period, and Duration — replacing the broken old API.
The var Keyword
Learn how Java 10's var keyword enables local variable type inference, its rules, and when to use or avoid it for cleaner code.
Records
Learn Java 16 Records — immutable data classes that auto-generate constructors, getters, equals, hashCode, and toString with minimal code.
Sealed Classes
Master Java 17 sealed classes — restrict class hierarchies with sealed, permits, non-sealed, and final for safer, more expressive code.