Exam. Objectives of OCAJP

TOPICS

Java Basics

• Define the scope of variables: class scope, method scope, loop scope.
• Define the structure of a Java class: interface, abstract class, and class
• Create executable Java applications with a main method: public static void main(String ... args)
• Import other Java packages to make them accessible in your code:  import static and import 

Working With Java Data Types

• Declare and initialize variables : 
• primitive and reference type.  init. block instance fields and static init. block. 
• Differentiate between object reference variables and primitive variables
• var. store reference to object; comparing the content, but not reference; 
• Read or write to object fields
• Explain an Object's Lifecycle (creation, "dereference" and garbage collection)
• reference = null; system.GC() suggest jvm to collect. 
• Call methods on objects
• Manipulate data using the StringBuilder class and its methods
• Creating and manipulating Strings

Using Operators and Decision Constructs  

• Use Java operators
• Use parenthesis to override operator precedence
• Test equality between Strings and other objects using == and equals ()
• Create if and if/else constructs
• Use a switch statement

Creating and Using Arrays

• Declare, instantiate, initialize and use a one-dimensional array
• Declare, instantiate, initialize and use multi-dimensional array
• *Declare and use an ArrayList

Using Loop Constructs

• Create and use while loops
• Create and use for loops including the enhanced for loop
• Create and use do/while loops
• Compare loop constructs
• Use break and continue  

Working with Methods and Encapsulation

• Create methods with arguments and return values
• Apply the static keyword  to methods and fields  
• Create an overloaded method
• Differentiate between default and user defined constructors
• Create and overload constructors
• Apply access modifiers
• Apply encapsulation principles to a class
• Determine the effect upon object references and primitive values when they are passed  into methods that change the values

Working with Inheritance

• Implement inheritance
• Develop code that demonstrates the use of polymorphism
• Differentiate between the type of a reference and the type of an object
• Determine when casting is necessary
• Use super and this to access objects and constructors
• Use abstract classes and interfaces

Handling Exceptions

• Differentiate among checked exceptions, RuntimeExceptions and Errors
• Create a try-catch block and determine how exceptions alter normal program flow
• Describe what Exceptions are used for in Java
• Invoke a method that throws an exception
• Recognize common exception classes and categories