what is difference between interface abstract class?
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Main difference is methods of a Java interface are implicitly abstract and cannot have implementations. A Java abstract class can have instance methods that implements a default behavior. ... A Java class can implement multiple interfaces but it can extend only one abstract class.
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Interfaces are completely empty shells that expect child classes to implement everything for them. On the other hand, abstract class can not only contain common piece of information by implementing inside them but also expect child classes to fill in the remaining gaps.
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The main difference between them is that the Builder pattern primarily describes the creation of complex objects step by step. In the Abstract Factory pattern, the emphasis is on families of objects-products. Builder returns the product in the last step.
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An interface contains behaviors that a class implements. A class may contain abstract methods, concrete methods. An interface contains only abstract methods. Members of a class can be public, private, protected or default.
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A class describes the attributes and behaviors of an object. An interface contains behaviors that a class implements. A class may contain abstract methods, concrete methods. An interface contains only abstract methods.
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An abstract method is like a prototype for a method, declaring the method's return type and parameter list but not providing an actual implementation of the method. You can't instantiate an abstract class. ... In other words, it must override each abstract method.
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The difference is that IList is an Interface and cannot be instantiated. List is a class and can be instantiated. Because that would require C# deriving from multiple classes, which it can't.
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A Java class can implement multiple interfaces but it can extend only one abstract class. 7. Interface is absolutely abstract and cannot be instantiated; A Java abstract class also cannot be instantiated, but can be invoked if a main() exists.
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The main difference between abstract class and final class in Java is that abstract class is a class with abstract and non-abstract methods and allows accomplishing abstraction, while final class is a class that restricts the other classes from accessing its data and methods.
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Interfaces cannot be instantiated, but rather are implemented. A class that implements an interface must implement all of the non-default methods described in the interface, or be an abstract class. ... Object (the root class of the Java type system); multiple inheritance of classes is not allowed.
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Main difference is methods of a Java interface are implicitly abstract and cannot have implementations. A Java abstract class can have instance methods that implements a default behavior. Variables declared in a Java interface is by default final. An abstract class may contain non-final variables.
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These two are quite different: Default methods are to add external functionality to existing classes without changing their state. And abstract classes are a normal type of inheritance, they are normal classes which are intended to be extended.
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An abstract class can have an abstract method without body and it can have methods with implementation also. ... An abstract class is mostly used to provide a base for subclasses to extend and implement the abstract methods and override or use the implemented methods in abstract class.
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Virtual methods have an implementation and provide the derived classes with the option of overriding it. Abstract methods do not provide an implementation and force the derived classes to override the method. So, abstract methods have no actual code in them, and subclasses HAVE TO override the method.
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Abstract methods can be either public, protected or default access (package visible). Unlike interfaces abstract classes can contain fields that are not static and final. *Abstract classes can have private methods, but not abstract private methods.
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Abstract classes are used to be inherited only. But when you inherited from a non abstract class you can create instance from both of derived and base classes. So we can say abstract classes are used to generate new types,to be inherited not to create instance !
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An abstract class is a way to achieve the abstraction in C#. An Abstract class is never intended to be instantiated directly. ... Like a class, Interface can have methods, properties, events, and indexers as its members. But interfaces will contain only the declaration of the members.