Java Core

«The Java Core» quest is intended for those who have already received basic Java training (by completing CodeGym's Java Syntax quest). Here you have to pass 10 fascinating levels where you will learn the basics of OOP, get acquainted with streams, serialization, and method overloading, and you'll learn a lot about interfaces and multiple inheritance. The training is no longer as simple as the «Java Syntax» quest, but regular practice (by completing tasks) will help you pass all 10 levels in this quest, and you'll be ready to complete mini-projects in the near future.
- Level 1
Locked Basics of OOP: basic principles, inheritance, encapsulation - Level 2
Locked Basics of OOP: overloading, polymorphism, abstraction, interfaces - Level 3
Locked Interfaces: comparison with an abstract class, multiple inheritance - Level 4
Locked Type casting, instanceof. A big task involving interfaces - Level 5
Locked Overloading methods, a feature of constructor calls - Level 6
Locked Introduction to threads: Thread, Runnable, start, join, interrupt, sleep - Level 7
Locked Introduction to threads: synchronized, volatile, yield - Level 8
Locked Introduction to streams: InputStream/OutputStream, FileInputStream, FileOutputStream - Level 9
Locked Introduction to streams: Reader/Writer, FileReader/FileWriter - Level 10
Locked Serialization