food class || show ,adding new item qyt , selling

using oops concept
Food class and create object , create method , constructs method

Sorting number using class and interface--

A small program use java object oriented program

abstract class in java

polymorphm java

inheritance in java

Inheritance in java is a mechanism in which one object acquires all the properties and behaviors of parent object.

The class which inherits the properties of other is known as subclass (derived class, child class) and the class whose properties are inherited is known as superclass (base class, parent class).

Inheritance represents the IS-A relationship, also known as parent-child relationship.

Example of Single Inheritance

Example of Multilevel Inheritance

Example of Heirarchical Inheritance

Polymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object. Any Java object that can pass more than one IS-A test is considered to be polymorphic

There are two types of polymorphism in java: compile time polymorphism and runtime polymorphism. We can perform polymorphism in java by method overloading and method overriding.

Example of method overloading

Example of method overriding

java progrma

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Java Object-Oriented Programming

Introduction to OOP :

What Is an Object?

An object is a software bundle of related state and behavior. Software objects are often used to model the real-world objects that you find in everyday life. 

What Is a Class?

A class is a blueprint or prototype from which objects are created. 

What Is Inheritance?

Inheritance provides a powerful and natural mechanism for organizing and structuring your software. 

What Is an Interface?

An interface is a contract between a class and the outside world. When a class implements an interface, it promises to provide the behavior published by that interface. 

What Is a Package?

A package is a namespace for organizing classes and interfaces in a logical manner. Placing your code into packages makes large software projects easier to manage.