Class and Object

Classand Object

Class vs Object • Let us consider the following scenario… • Class defines a set of attributes/fields and a set of methods/services. • Object is an instance of a class. Object allows you to call the methods defined in the Class

Class Computer • In Class Computer, you can declare all relevant attributes. • In Class Computer, you can define/implement all services/methods (non static) Computer class Computer { private string mfr; private int year; … public void set_mfr(…) {…} public string get_mfr() {…} public void editAfile(){… ;save(..);} } • - String: mfr • Int: year • Double: price + set_mfr(…){..} + get_mfr(){..} + editAfile() {…} Every attribute MUST be private AND you must provide Two methods related to each attribute to allow set a value And get the value !!!

Object Computer • You cannot use any services provided by a computer until you have a computer. Computer myPC = new Computer(“IBM”, 2012,1000); myPC.editAfile(); Computer mylaptop= new Computer(“Dell”, 2010,900); mylaptop.editAfile();

USB Flash Drive • Assume USB Flash correctly implements the save data service via method save() • Where should you put method save() • Copy save() method to Class Computer • Create a separate class for USB Flash Drive where save() is provided.

Class USBFlashDrive • We better introduce a new class USBFlashDriveand save() is defined as a method in that class Computer class Computer { private string mfr; private int year; … public void set_mfr(…) {…} public string get_mfr() {…} public void editAfile(){… ; ;} } • - String: mfr • Int: year • Double: price private USBFlashDriveusb; + set_mfr(…){..} + get_mfr(){..} + editAfile() {…} public void set_usb(USBFlashDrive u){…} public USBFlashDriveget_usb(){…} usb.save() USBFlashDrive - String: loc + save() {…}

Now You can use the save() service • You need to buy a computer and a usb flash drive Computer mylaptop = new Computer(“Dell”, 2010,900); USBFlashDrivemyusb = new USBFlashDrive(…); mylaptop.editAfile(); mylaptop.setusb(myusb); Don’t forget to connect myusb to mylaptop!!!

Class and Object

Class and Object

Presentation Transcript

The Object class hierarchy

Class Object

Class and Object

Object vs Class composition

Object-Oriented Design Inheritance and Class Examples

Class Object and class Class

Object-oriented modeling Class/Object Diagrams

Object and Class Structuring

Object Oriented Programming Class

Paradigm of the object oriented programming, class, object

Class and Object Diagrams

Object and Class Diagrams

Object-Oriented Design and Class Diagrams

Object and Class Creational Design Patterns

Class And Object

The Object class

Object Class Code Training

OOP Class vs. Object

Object and Class Creational Design Patterns

Object vs Class composition