tailieunhanh - Object-Oriented Programming: Intefaces

Object-Oriented Programming: Inteface's Content is Defining an interface, Implementing an interface, Using an interface as a type, Rewriting interfaces; Interfaces are used to encode similarities which the classes of various types share but do not necessarily constitute a class relationship. | Lecture 4: Interfaces Lê Hồng Phương phuonglh@ Department of Mathematics, Mechanics and Informatics, Vietnam National University, Hanoi Content ● Defining an interface ● Implementing an interface ● Using an interface as a type ● Rewriting interfaces ● Examples 2012-2013 Object-Oriented Programming: Intefaces 2 Defining an interface ● ● Interfaces are used to encode similarities which the classes of various types share but do not necessarily constitute a class relationship. Examples: – A human and a parrot can both whistle. It does not make sense to represent Human and Parrot as subclasses of Whistle. – A person and a rectangle can both measurable by some criterion (., by weight for persons, by area for rectangles). 2012-2013 Object-Oriented Programming: Intefaces 3 Defining an interface ● ● In object-oriented languages, an interface is an abstract type that is used to specify an interface (in the generic sense of the term). An interface contains only – method signatures (prototypes) – constant declarations A purely abstract method. public interface Relatable { public int isLargerThan(Relatable other); } Note the semicolon 2012-2013 Object-Oriented Programming: Intefaces 4 Defining an interface ● An interface can extends others: public interface GroupedInterface extends Interface1, Interface2, Interface3 { double E = ; void doSomething(int i, double x); int doSomthingElse(String s); } A constant Two method signatures How many method signatures does the GroupedInterface have? 2012-2013 Object-Oriented Programming: .

• Kỹ thuật lập trình
• Object Oriented Programming
• Defining an interface
• Implementing an interface
• Using an interface as a type
• Rewriting interfaces
• Constant declarations