JAVA
Java — Intermediate
Write modern, idiomatic Java: design with interfaces and polymorphism, model data with records, enums and sealed types, master the Collections framework and generics, handle exceptions properly, process data with lambdas and streams, and work with files.
Lessons
- 1Inheritance, Interfaces & Polymorphismextends, abstract classes, interfaces with default methods, and polymorphism.
- 2Records, Enums, Sealed Types & Pattern MatchingConcise data classes, fixed sets of constants, closed type hierarchies and switch patterns.
- 3The Collections FrameworkList, Set, Map and Deque — choosing the right one, iterating, sorting with Comparator.
- 4equals, hashCode & ComparableObject identity vs equality, the equals/hashCode contract, natural ordering with Comparable and custom orders with Comparator.
- 5GenericsType-safe reusable classes and methods, bounded types and wildcards.
- 6ExceptionsChecked vs unchecked exceptions, try / catch / finally, try-with-resources and custom exceptions.
- 7Lambdas, Optional & StreamsFunctional interfaces, method references, Optional, and filter / map / collect pipelines.
- 8Regular Expressions & Text ProcessingPattern and Matcher, matches vs find, named groups, replaceAll, split, StringBuilder and text blocks.
- 9Files & I/O with java.nioRead and write files with Path and Files, process CSV lines, and walk directories.