Java Core: OCA/OCP preparation

Java Technology and environment

• Java Technology and the Java development
• Key features of the Java language

Java Primitive Data Types and String APIs

• Variables declaration and initialization
• The scope of variables
• Local variable type inference
• Creation and manipulation with Strings
• Data manipulation using the StringBuilder class and its methods

Java Arrays

• Declaration, instantiation, initialization and the usage of one-dimensional array
• Declaration, instantiation, initialization and the usage of two-dimensional array

Methods

• Creating methods and constructors with arguments and return values
• Creating and invoke overloaded methods
• Applying the static keyword to methods and fields

Reusing Implementations Through Inheritance

• Creating and use subclasses and superclasses
• Creating and extend abstract classes
• Enabling polymorphism by overriding methods
• Utilizing polymorphism to cast and call methods, differentiating object type versus reference type
• Distinguishing overloading, overriding, and hiding

Handling Exceptions

• Understanding of Exception handling and differentiation among checked, unchecked exceptions, and Errors
• Creating try-catch blocks and determine how exceptions altering program flow
• Creating and invoking a method that throws an exception

Creating a Simple Java Program

• Creating an executable Java program with a main class
• Compiling and run a Java program from the command line
• Creating and importing packages

Using Operators and Decision Constructs

• Usage parentheses to override operator precedence
• Usage of control statements including if, if/else, switch
• Usage of do/while, while, for and for each loops, including nested loops, use break and continue statements

Objects and Classes

• • • Declaring and instantiating Java objects, and explain objects’ lifecycles (including creation, dereferencing by reassignment, and garbage collection)
    • Defining the structure of a Java class
    • Reading or writing to object fields

Encapsulation

• Appling access modifiers
• Appling encapsulation principles to a class

Programming Abstractly Through Interfaces

• Creating and implementing interfaces
• Distinguishing class inheritance from interface inheritance including abstract classes
• Declare and use List and ArrayList instances
• Understanding Lambda Expressions

Understanding Modules

• Description of the Modular JDK
• Modules declaration and enable access between modules
• Description how a modular project is compiled and run