Overriding means to\u00a0extend\u00a0or to\u00a0pass\u00a0over something, especially to\u00a0overlap the previous described functionality. So Method Overriding means to re-write the previous described method again of Parent Class in Sub class with different functionality.<\/p>\n
In Method Overriding, we overrides the method of Super Class in Sub Class. The method overriding is also called Run time Polymorphism or Dynamic Binding.<\/p>\n
Before discussing Method Overriding<\/strong>, let us revise our concept of Inheritance<\/a><\/strong>. Inheritance is a phenomena in which one class extends the properties( i.e. methods and fields) of another class. It makes our programming much easier as previously defined code is reused, and we can add our own functionality.<\/p>\n The class which extends the properties of another class is called Sub-Class or Child-Class or Derived-Class. And the class whose methods and fields or any other property is inherited is called Super-Class or Base-Class or Parent-Class.<\/p>\n Why Method Overriding?<\/strong><\/span> Now let us understand the problem that we face without method overriding.<\/p>\n In the following program we have Animal and Horse classes. In Animal Class<\/strong> we have defined a method which prints \u201cAnimal is running\u201d.<\/strong>\u00a0In Horse class<\/strong> we have used the already defined method run()<\/strong>\u00a0of Animal Class as shown:<\/p>\n Below is code of Animal class:<\/p>\n Below is the code of Horse class which extend Animal class<\/p>\n Output:<\/strong><\/span><\/p>\n Problem & Solution:<\/strong><\/span> But the problem here is if we have to give specific implementation to Horse Class object, that \u201cHorse is running\u201d then how can we do that? The answer is Method overriding! So to give specific implementation to parent class method in sub-class we need Method Overriding. So let\u2019s come to Method Overriding:<\/strong><\/span><\/p>\n Lets discuss the same example again using method overriding:<\/strong><\/p>\n Below is the Horse class code which override run method of Animal class after extending it:<\/p>\n Output:<\/strong><\/span><\/p>\n Here we see method run() is defined again in sub class Horse or in other words method run() is overlapped in the child class, giving it a different functionality. So now we have given specific implementation to the child class run() method.<\/p>\n Important Note: <\/strong><\/span>Method Overriding is also called as Run time Polymorphism or Dynamic Binding. This is due to the fact that the compiler doesn’t necessarily know what type of object is being passed at compile-time.<\/p>\n When you override any method, it is optional but recommended in JAVA to write @Override just above the method which you are overriding. This helps JAVA compiler to know that we want to override a method here which is already present in Parent class. But in-case if it is not present the compiler will give error letting us know that there is no method like that in Parent class.<\/p>\n Below is the Syntax of Method Overriding using @Override<\/strong><\/p>\n Lets take a real life situation where we will need Method Overriding to code in JAVA.<\/p>\n Consider a case, where Hospital provides no. of patients admitted in it. But number of patients varies with the different hospitals, For example Health India hospital has 1657 patients, IVY hospital has 2965 patients\u00a0 and Apollo Hospital has 1631 patients.<\/p>\n Below is code of Hospital parent class which has one method getNumberOfPatients() and sub class HealthIndia, IVY and Apolo class which extends parent class & override its method.<\/p>\n Below is the code of MethodOverriding class which is the main class. Here we will create object for each sub class and run getNumberOfPatients() method on those objects to get patient details of each Hospital.<\/p>\n Now we have seen different hospitals are calling same method, but at run time it has to be decided which class method is called depending on which class object is calling the getNumberOfPatients()<\/span><\/strong> method.<\/p>\n Method overloading:<\/span><\/strong><\/p>\n Method Overriding:<\/strong><\/span><\/p>\n Overriding means to\u00a0extend\u00a0or to\u00a0pass\u00a0over something, especially to\u00a0overlap the previous described functionality. So Method Overriding means to re-write the previous described method again of Parent Class in Sub class with different functionality. In Method Overriding, we overrides the method of Super Class in Sub Class. The method overriding is also called Run time Polymorphism or Dynamic … Continue reading Method Overriding Tutorial With Examples In JAVA<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"home.php","meta":{"footnotes":""},"class_list":["post-533","page","type-page","status-publish","hentry"],"psp_head":"class Animal {\r\n\r\nvoid run(){\r\nSystem.out.println(\"Animal is running\");\r\n}\r\n\r\n}<\/pre>\npublic class Horse extends Animal\r\n{\r\npublic static void main(String args[]){\r\nHorse horse = new Horse(); \/\/Horse class object is created\r\nhorse.run();\r\n}\r\n\r\n}\r\n<\/pre>\nAnimal is running\r\n<\/pre>\n
\n<\/em><\/p>\n\n
class Animal {\r\n\r\nvoid run()\r\n{\r\nSystem.out.println(\"Animal is running\");\r\n}\r\n\r\n}<\/pre>\npublic class Horse extends Animal\r\n\r\n{\r\n\/\/run() Method is overridden in Sub-Class\r\nvoid run(){\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\r\nSystem.out.println(\"Horse is running\");\r\n}\r\n\r\npublic static void main(String args[]){\r\nHorse horse = new Horse();\r\nhorse.run();\r\n}\r\n}\r\n<\/pre>\nHorse is running\r\n<\/pre>\n
\nWriting @Override Annotation Is Optional<\/strong><\/h4>\n
class Parent{\r\nmethod(){\r\n\/\/Add Functionality here\r\n}\r\n}\r\n\r\nclass Subclass extends Parent{\r\n@Override\r\nmethod(){\r\n\/\/New Functionality here for method\r\n}\r\n}<\/pre>\n
\nReal life example\u00a0of Method Overriding :<\/strong><\/span><\/h4>\n
class Hospital{\r\n\r\n\tint getNumberOfPatients()\r\n\r\n\t{\r\n\r\n\t\treturn 0;\r\n\r\n\t}\r\n\r\n}\r\n\r\nclass HealthIndia extends Hospital{\r\n\r\n\t@Override\r\n\tint getNumberOfPatients()\r\n\r\n\t{\r\n\r\n\t\treturn 1657 ;\r\n\r\n\t}\r\n\r\n}\r\n\r\nclass IVY extends Hospital{\r\n\t@Override\r\n\tint getNumberOfPatients()\r\n\r\n\t{\r\n\r\n\t\treturn 2965 ;\r\n\r\n\t}\r\n\r\n}\r\n\r\nclass Apollo extends Hospital{\r\n\t@Override\r\n\tint getNumberOfPatients()\r\n\r\n\t{\r\n\r\n\t\treturn 1631 ;\r\n\r\n\t}\r\n\r\n}<\/pre>\npublic class MethodOverriding{\r\n\r\n\tpublic static void main(String args[]){\r\n\r\n\t\tHealthIndia healthIndia=new HealthIndia();\r\n\r\n\t\tIVY ivy=new IVY();\r\n\r\n\t\tApollo apollo=new Apollo();\r\n\r\n\t\tint healthIndiaPatients= healthIndia.getNumberOfPatients();\r\n\r\n\t\tint iVYPatients= ivy.getNumberOfPatients();\r\n\r\n\t\tint apolloPatients= apollo.getNumberOfPatients();\r\n\r\n\t\tSystem.out.println(\"Health India hospital patients: \"+ healthIndiaPatients);\r\n\r\n\t\tSystem.out.println(\"IVY hospital Patients: \"+ iVYPatients);\r\n\r\n\t\tSystem.out.println(\"Apollo hospital Patients: \" +apolloPatients);\r\n\r\n\t}\r\n\r\n}<\/pre>\nOutput:<\/strong><\/span><\/h4>\n
Health India hospital patients: 1657\r\nIVY hospital Patients: 2965\r\nApollo hospital Patients: 1631\r\n<\/pre>\n
\nAdvantages of using Method Overriding:<\/strong><\/span><\/h4>\n
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\nRules of Method Overriding :<\/strong><\/span><\/h4>\n
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\nDifference between Method Overloading and Method Overriding:<\/span><\/strong><\/h4>\n
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\nImportant Points: <\/strong><\/span><\/h4>\n
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\nQuick Revision points:<\/strong><\/span><\/h4>\n
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