tài liệu tự học java cho người mới bắt đầu

Session 6 Module 8: More on Classes Module 9: Exceptions More on class & Exception / Session6 / 2 of 37 Module 7 - Review  Inheritance  Overloading of methods  Using abstract keyword  Using final keywords  Interfaces More on class & Exception / Session6 / 3 of 37 Module 8 - Objectives  Class variables  Nested class More on class & Exception / Session6 / 4 of 37 Class variables  Are declared using the static keyword  Once the value is modified, all instances of the class are updated to share the same value More on class & Exception / Session6 / 5 of 37 Access Class variables  Can also be manipulated without creating an instance of the class  Are referenced by the class name itself More on class & Exception / Session6 / 6 of 37 Static methods  Also known as class methods, do not have reference to any instance variable in a class, used to access class variables and methods.  The keyword this cannot be used inside a static method. More on class & Exception / Session6 / 7 of 37 Accessing class method  Can be accessed by using a class name  or  an instance name (not recommend) More on class & Exception / Session6 / 8 of 37 Static initializer  Is a block of code embraced in curly braces  It is preceded by the static keyword  It initializes the static variables in class  The static initialization block can reference only class variables that have been declared before it More on class & Exception / Session6 / 9 of 37 Nested class  A class defined within another class  It can have access to members of the outer class (enclosing class) even if the members are declared private  It can be used for:  Allow logical grouping of classes  Increases encapsulation  More maintainable code More on class & Exception / Session6 / 10 of 37 Different type of nested class  Member classes or non-static nested classes  Local classes  Anonymous classes  Static nested classes [...]... instantiated to access the instance variables and methods of the enclosing class More on class & Exception / Session6 / 14 of 37 Module 9 - Objectives Introduction to Exceptions  Exception handling in Java  User defined exceptions  Assertions  More on class & Exception / Session6 / 15 of 37 Introduction to Exceptions Explain the concept of Exceptions  Identify the different types of Exceptions ... 22 of 37 Types of Unchecked Exceptions All Unchecked exceptions are directly or indirectly derived from the RuntimeException class More on class & Exception / Session6 / 23 of 37 Exception handling in Java State the use of try-catch block  Describe the use of finally block  State the flow of execution in an exception handling block  Describe the use of throw and throws keyword  Describe the use . Session6 / 15 of 37 Module 9 - Objectives  Introduction to Exceptions  Exception handling in Java  User defined exceptions  Assertions More on class & Exception / Session6 / 16 of 37 Introduction