What is the diff between interface and abstract class?

Interface is a class construct with methods having no functionality.Advantage of an Interface will come to the picture if the porgrammerwants to call the methods in such a manner where he/she can implementthose methods according their requirement/usage in a class construct.Abstraction is the process of getting the required by hiding unnecessary data objects.An Abstract Class can have the methods with/withoutfuncationality.By extending a normal class to the abstract class,the class will not become abstract.A method has to be defined as abstract in an abstract class elseit is a normal method.
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