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What is OOPs in java?<\/h3>\n\n\n\n
Java is a secured programming language developed by sun microsystem. James Gosling is the founder of Java. OOPs is a primary source code to implement the data in the system. it also manipulates data that represents to focus on the object data.<\/p>\n\n\n\n
What is OOPs concept in java?<\/h3>\n\n\n\n
Programming’s essential tenets based on object-oriented programming (OOP) ideas. The goal of OOPs in Java is to increase code readability and reuse by defining Java programs.<\/p>\n\n\n\n
Java datatype and variable<\/p>\n\n\n\n
<\/p>\n\n\n\n
What is a data type?<\/h3>\n\n\n\n
A data type is a variable that stores in the form of size and values.<\/p>\n\n\n\n
<\/p>\n\n\n\n
Declaring a variable<\/strong><\/p>\n\n\n\n int u,v,w;<\/p>\n\n\n\n Char z;<\/p>\n\n\n\n Initialize a variable<\/strong><\/p>\n\n\n\n x=\u201dz\u201d;<\/p>\n\n\n\n y=2<\/p>\n\n\n\n Now it is int a=5,b=8<\/p>\n\n\n\n Variable types of oops in java<\/strong><\/p>\n\n\n\n 1. local<\/p>\n\n\n\n 2. instance<\/p>\n\n\n\n 3. static<\/p>\n\n\n\n Example<\/strong><\/p>\n\n\n\n Class main<\/p>\n\n\n\n Static int x=10;<\/p>\n\n\n\n Int data=50;<\/p>\n\n\n\n Void method()<\/p>\n\n\n\n Int y= 20;<\/p>\n\n\n\n }<\/p>\n\n\n\n }<\/p>\n\n\n\n <\/p>\n\n\n\n Programming’s fundamental building block is an object. Object recognizes their distinctive names. an object defined as a collection of data members and operations also called methods.<\/p>\n\n\n\n For example, a car is an object which has attributes like color, model, and year of manufacturing. and its functions start, stop, and move.<\/p>\n\n\n\n <\/p>\n\n\n\n A class can form by grouping objects with similar properties.<\/p>\n\n\n\n Example<\/strong>: we have a Class of Cars in which Santro Xing, Alto, and WaganR represent individual Objects. <\/p>\n\n\n\n In this context, each Car Object will have its Model, Year of Manufacture, Color, Top Speed, Engine Power, and so on, which form Car Class Properties, and the associated actions, i.e., object functions like Start, Move and Stop, which form Car Class Methods.<\/p>\n\n\n\n <\/p>\n\n\n\n Grouping of data and methods into a single entity known as data encapsulation or data hiding.<\/p>\n\n\n\n Encapsulation is a data hiding used to protect data from the outside world. <\/p>\n\n\n\n <\/p>\n\n\n\n It is extending an existing class to create a new one. Inheritance is the process by creating a new class by which objects of one class inherit the properties of objects of a different class.<\/p>\n\n\n\n <\/p>\n\n\n\n A polymorphic operation displays various behavior depending on the situation. The type of data used in the process, which determines the behaviour.<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Suppose you want to create a new account with functions like Account number, account balance.<\/p>\n\n\n\n First, we will apply this in an unstructured programming language. Unstructured programming languages were the first of all programming languages.<\/p>\n\n\n\n Int account_num=5;<\/p>\n\n\n\n Int account_bal=1000;<\/p>\n\n\n\n Again a deposit made<\/p>\n\n\n\n Account_bal=account_bal+1000<\/p>\n\n\n\n Display the account balance<\/p>\n\n\n\n printf(\u201caccount_num=%d,account bal\u201d)<\/p>\n\n\n\n printf(\u201caccount_bal=%d,account bal\u201d)<\/p>\n\n\n\n Now withdraw 500<\/p>\n\n\n\n account_bal=account_bal-500<\/p>\n\n\n\n Now again you need to display the account balance<\/p>\n\n\n\n <\/p>\n\n\n\n In this unstructured program, codes will get repeated again and again<\/strong><\/p>\n\n\n\n We will apply the same code to Structured programming<\/p>\n\n\n\n printf(\u201caccount_num=%d,account bal\u201d)<\/p>\n\n\n\n printf(\u201caccount_bal=%d,account bal\u201d)<\/p>\n\n\n\n Void showdata()<\/p>\n\n\n\n Here we use void call data to call the function itself. whenever needed it calls a function <\/p>\n\n\n\n <\/p>\n\n\n\n The same code we will apply in oops concepts(object-oriented programming)<\/strong><\/p>\n\n\n\n Class account<\/p>\n\n\n\n {<\/p>\n\n\n\n Int account_num;<\/p>\n\n\n\n Int account_bal;<\/p>\n\n\n\n Public void showdata()<\/p>\n\n\n\n {<\/p>\n\n\n\n system.out.println(\u201caccount num\u201d+account_num)<\/p>\n\n\n\n system.out.println(\u201caccount bal\u201d+account_bal)<\/p>\n\n\n\n }<\/p>\n\n\n\n }<\/p>\n\n\n\n <\/p>\n\n\n\n A software program is an fundamental aspect which has the ability to conduct specific operations on data and have data available. The idea of merging data and operations came from software programming experts. Object Oriented Programming, or concepts of OOPs in java, was thus born.<\/p>\n\n\n\n Int account_num=5;\u2192DATA<\/p>\n\n\n\n Int account_bal=1000;<\/p>\n\n\n\n <\/p>\n\n\n\n Void showdata()\u2192ACTIONS<\/p>\n\n\n\n Objects & classes<\/strong><\/p>\n\n\n\n OOPs is a concept of java in a class, all of an object’s functions and data converted to user-defined data types. A class is a “data type,” and an object is a “variable” of that type. After a class created, the maximum amount of its components get constructed.<\/p>\n\n\n\n Syntax<\/strong><\/p>\n\n\n\n Access modifier class<class name> <\/p>\n\n\n\n Create the class school. To create an object, specify the class name, followed by the object name, and use the keyword new.<\/p>\n\n\n\n <\/p>\n\n\n\n school Myobj= new school ()<\/p>\n\n\n\n Created a java file called myschool.java and prints henry harvin on the screen. <\/p>\n\n\n\n <\/p>\n\n\n\n You can also create many objects in the same class<\/p>\n\n\n\n The \u201csuperclass\u201d is the existing class and the \u201csubclass\u201d is the new class. superclass derived from the child class and subclass derived from the parent class.<\/p>\n\n\n\n Syntax<\/strong><\/p>\n\n\n\n Class derived- class extends base-class<\/p>\n\n\n\n {<\/p>\n\n\n\n \/\/methods and fields<\/p>\n\n\n\n }<\/p>\n\n\n\n Example<\/strong><\/p>\n\n\n\n Multilevel inheritance occurs when there is a chain of inheritance.<\/p>\n\n\n\n Hierarchical inheritance occurs when two or more classes inherit the same class.<\/p>\n\n\n\n Example course and primary school inherits the school class,so there is hierarchical inheritance.<\/p>\n\n\n\n Hybrid inheritance is a composition of two or more of the preceding types of inheritance.java does not support hybrid inheritance.it can achieve only through interface.<\/a><\/strong><\/p>\n\n\n\n Example<\/p>\n\n\n\n Multiple inheritance is not achieved through class but supported through interfaces.<\/p>\n\n\n\n As seen in the example, we make an interface to extend one of these interfaces and to specify the same function.<\/p>\n\n\n\n An abstract class is one that has the keyword abstract in its declaration.<\/p>\n\n\n\n Syntax<\/strong><\/p>\n\n\n\n Abstract class main()<\/p>\n\n\n\n {<\/p>\n\n\n\n Public abstract void hello()<\/p>\n\n\n\n }<\/p>\n\n\n\n Declaring an Abstract class<\/strong><\/p>\n\n\n\n Abstract class a()<\/p>\n\n\n\n Declaring an Abstract method<\/strong><\/p>\n\n\n\n Abstract void hello()<\/p>\n\n\n\n Example 2:<\/p>\n\n\n\n Points to remember<\/strong><\/p>\n\n\n\n Data encapsulation restricts the class fields and methods and modification by exterior classes. Moreover, this aids in data protection.<\/p>\n\n\n\n Example<\/strong><\/p>\n\n\n\n There are two methods in abstraction.<\/p>\n\n\n\n \u201cread-only\u201d and \u201cwrite only\u201d called getter-setter methods in java. It provides control over the data.<\/p>\n\n\n\n certainly, if you want to set the value of id which should be greater than 100 only, you can write the logic inside the setter method. <\/p>\n\n\n\n You can write the logic not to store the negative numbers in the setter methods.<\/p>\n\n\n\n Example of getter and setter method in encapsulation<\/strong><\/p>\n\n\n\n Here we have two types of polymorphism<\/p>\n\n\n\n 1. Runtime<\/p>\n\n\n\n 2. Compile time<\/p>\n\n\n\n Example for runtime polymorphism<\/strong><\/p>\n\n\n\n primary.java<\/p>\n\n\n\n <\/p>\n\n\n\n It shows the output as nursery<\/p>\n\n\n\n <\/p>\n\n\n\n Middle.java<\/p>\n\n\n\n It shows the output as 6to8<\/p>\n\n\n\n <\/p>\n\n\n\n We defined the method sound() and have many implementations of it in the various sub-classes, as seen in the sample above.<\/p>\n\n\n\n The example we provided below is a runtime polymorphism<\/p>\n\n\n\n There are three overloads of the method demo() in this case the first has one int parameter, the second has two int parameters,third has a double parameter. <\/p>\n\n\n\n To specify the method we call the arguments to supply.Compile time polymorphism is the name given to the type of polymorphism that occurs when code is being built at runtime.<\/p>\n\n\n\n <\/p>\n\n\n\n OOPs concepts in Java.<\/strong><\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Best institute to learn Java for beginners.<\/strong><\/p>\n\n\n\nOOPs concept in java<\/h3>\n\n\n\n
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Object<\/strong><\/h2>\n\n\n\n
Classes<\/h2>\n\n\n\n
Abstraction and encapsulation<\/h2>\n\n\n\n
Inheritance<\/h2>\n\n\n\n
polymorphism<\/h2>\n\n\n\n
Benefits of OOPs in java<\/h2>\n\n\n\n
Concepts of OOPs comparison with different programming languages using an example <\/h3>\n\n\n\n
An illustration of how java’s oops principles differ from other programming paradigms<\/h4>\n\n\n\n
OOPS concepts in java with example<\/h2>\n\n\n\n
{
Data member;
Method;
}<\/p>\n\n\n\npublic class School\n{\nString x=\"henry harvin\";public static void main(String[] args) \n{\nschool myobj=new school();\nSystem.out.println(myobj.x);\n}\n}<\/code><\/pre>\n\n\n\nPublic class myschool\n{\nstring x=henry harvin;\nstring y=yyy;\n}\nClass courses\n{\nPublic static void main (string [ ] args)\n{\nMyschool myobj1=new myobj1();\nMyschool myobj2=new myobj2();\nsystem.out.println(myobj1.x);\nsystem.out.println(myobj2.y);\n}\n}\n<\/code><\/pre>\n\n\n\nPoints to remember<\/strong><\/h2>\n\n\n\n
Inheritance<\/h2>\n\n\n\n
Types of inheritance <\/h3>\n\n\n\n
Single inheritance<\/h3>\n\n\n\n
class school\n{ \nvoid name()\n{\nSystem.out.println(\"course...\");} \n} \nclass course extends school\n{ \nvoid place()\n{\nSystem.out.println(\"place...\");\n} \n} \nclass TestInheritance{ \npublic static void main(String args[]){ \ncourse d = new course(); \nd.name(); \nd.place(); \n}\n} \n\n<\/code><\/pre>\n\n\n\nMultilevel inheritance<\/h3>\n\n\n\n
class school\n{ \nvoid name()\n{\nSystem.out.println(\"name\");\n} \n} \nclass course extends school\n{\nvoid place()\n{\nSystem.out.println(\"place\");\n} \n} \nclass primaryschool extends course\n{ \nvoid course()\n{\nSystem.out.println(\"course\");\n}\n} \nclass Testinheritance2\n{ \npublic static void main(String args[])\n{ \nprimaryschool d=new primaryschool();\nd.course();\nd.place();\nd.name();\n}\n} \n<\/code><\/pre>\n\n\n\nHierarchical inheritance<\/h3>\n\n\n\n
class school\n{ \n\nvoid name()\n{\nSystem.out.println(\"name...\");\n} \n} \nclass course extends school\n{ \nvoid course()\n{\nSystem.out.println(\"course...\");\n} \n} \nclass primaryschool extends school\n{ \nvoid nursery()\n{\nSystem.out.println(\"nursery...\");\n} \n} \nclass TestInheritance3\n{ \npublic static void main(String args[])\n{ \nprimaryschool d=new primaryschool(); \nd.name(); \n\/\/d.course();\nd.nursery(); \n }\n } \n<\/code><\/pre>\n\n\n\n Hybrid inheritance<\/h3>\n\n\n\n
class School\n{\n}\nclass primaryschool extends School\n{\n}\nclass middleschool extends School\n{\n}\nclass highschool extends primaryschool \n{\n public static void main(String args[])\n {\n School s = new School();\n primaryschool p = new primaryschool();\n middleschool m = new middleschool();\n \n System.out.println(s instanceof School);\n System.out.println(p instanceof primaryschool);\n System.out.println(m instanceof School);\n }\n}\n<\/code><\/pre>\n\n\n\nMultiple inheritance<\/h3>\n\n\n\n
Public interface interfaceA\n{\nPublic void hello();\n}\n Interface b.java\nPublic interface interface\n{\nPublic void hello();\n}\n<\/code><\/pre>\n\n\n\nInterfaceC.java \n\nPublic interface interfaceC extends interfaceA,interfaceB\n{\nPublic void hello();\n}\n<\/code><\/pre>\n\n\n\nAbstraction<\/h2>\n\n\n\n
abstract class school\n{ \n abstract void name(); \n} \nclass primary extends school\n{ \nvoid name()\n{\nSystem.out.println(\"good\");\n} \npublic static void main(String args[])\n{ \n school obj = new primary(); \n obj.name(); \n} \n} \n<\/code><\/pre>\n\n\n\nabstract class Bank\n{ \nabstract int getRateOfInterest(); \n} \nclass SBI extends Bank\n{ \nint getRateOfInterest()\n{return 5;\n} \n} \nclass PNB extends Bank\n{ \nint getRateOfInterest()\n{\nreturn 6;\n} \n} \n \nclass TestBank\n{ \npublic static void main(String args[])\n{ \nBank b; \nb=new SBI(); \nSystem.out.println(\"Rate of Interest is: \"+b.getRateOfInterest()+\" %\"); \nb=new PNB(); \nSystem.out.println(\"Rate of Interest is: \"+b.getRateOfInterest()+\" %\"); \n}\n} \n<\/code><\/pre>\n\n\n\nEncapsulation<\/h2>\n\n\n\n
Public class school\nPrivate string Name;\nPublic string getName()\n{\nReturn name;\n}\nPublic void setName(String name)\n{\nthis.name=name\n}\n}\n<\/code><\/pre>\n\n\n\nclass school\n{ \nprivate int name;\nprivate int regno; \n \/\/ getter method\n\tpublic int getregno() \n{\n return this.regno=num;\n }\n \/\/ setter method\n\tpublic void name \n{\n this.name;\n }\n}\n<\/code><\/pre>\n\n\n\nPolymorphism<\/h2>\n\n\n\n
Public class school\nPublic void class ()\n{\nsystem.out.println(\u201cschool is good\u201d);\n}\n}\n<\/code><\/pre>\n\n\n\nClass primary extends school\n{ \/\/override\/\/\nPublic void class()\n{\nsystem.out.println(\u201cnursery\u201d);\n}\nPublic static void main(string args[])\n{\nSchool obj=new primary();\nobj.class();\n}\n}\n<\/code><\/pre>\n\n\n\nClass middle extends school\n{ \/\/override\/\/\nPublic void class()\n{\nsystem.out.println(\u201c6to8\u201d);\n}\nPublic static void main(string args[])\n{\nSchool obj=new middle();\nobj.class();\n}\n}\n\n<\/code><\/pre>\n\n\n\nClass school\n{\nVoid demo (int a)\n{\nsystem.out.println(\u201ca:\u201d +a);\n}\nVoid demo (int a,int b)\n{ \nsystem.out.println(\u201ca and b:\u201d + a+\u201d,\u201d + b);\n}\nSecond demo (second a)\nsystem.out.println(\u201csecond a:\u201d+a);\nReturn a*a;\n}}\n\nClass method\n{\nPublic static void main(string args[])\n{\n Method obj=new method();\nSecond result;\nobj.demo(2);\nobj.demo(2.4);\nresult=obj.demo(4,4);\nsystem.out.println(\u201coutput:\u201d + result);\n}\n}\n<\/code><\/pre>\n\n\n\nConclusion<\/h2>\n\n\n\n