An Abstract<\/strong> class is a class whose objects can\u2019t be created. It is a kind of guideline or a template for other classes. An abstract class should contain at least one abstract method (method without any implementation or method body).<\/p>\n Syntax of writing Abstract classes:<\/strong><\/p>\n Get to know more about Java Inheritance<\/a> in detail with Techvidvan.<\/strong><\/em><\/p>\n Check out the different Java Methods<\/a> you didn’t know about.<\/strong><\/em><\/p>\n Syntax of declaring abstract methods:<\/strong><\/p>\n Example of Abstract class:<\/strong><\/p>\n Output:<\/strong><\/p>\n An interface<\/strong> is another building block of Java which is a blueprint or template of a class. It is much similar to the Java class but the only difference is that it has abstract methods and static constants.<\/p>\n There can be only abstract methods in an interface, that is there is no method body inside these abstract methods. The class that implements the interface should be declared as abstract, otherwise, all the methods of the interface need to be defined in the class.<\/p>\n![\"difference](\"https:\/\/techvidvan.com\/tutorials\/wp-content\/uploads\/sites\/2\/2020\/03\/abstract-class-vs-interface-in-java-1.jpg\")
<\/a><\/p>\nAbstract Class In Java<\/h3>\n
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abstract class TestAbstractClass\n{\n public abstract void abstractMethod();\n public void normalMethod()\n {\n \/\/method body\n }\n}<\/pre>\nReasons For Using Abstract Class in Java<\/h4>\n
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Abstract Methods in Java<\/h4>\n
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access-specifier abstract return-type method-name();<\/pre>\n
package com.techvidvan.abstractclass;\n\/\/parent class\nabstract class Animal\n{\n \/\/concrete method\n public void show1()\n {\n System.out.println(\"Concrete method of parent class Class\");\n }\n \/\/abstract method\n abstract public void show2();\n }\n\/\/child class\nClass Dog extends Animal\n{\n \/\/ Must Override this method while extending the parent class\n public void show2()\n {\n System.out.println(\"Overriding abstract method of parent class\");\n }\n\n \/\/Overriding concrete method is not compulsory\n public void show1()\n {\n System.out.println(\"Overriding concrete method of parent class\");\n }\n}\npublic class AbstractClassDemo\n{\n public static void main(String[] args)\n {\n Dog obj = new Animal();\n obj.show2();\n obj.show1();\n }\n}<\/pre>\n
\nOverriding concrete method of parent class<\/div>\nRules to be followed for Abstract Class<\/h4>\n
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Interfaces in Java<\/h3>\n