Difference between abstract and interface

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Accepted Answer

Abstract classes are classes that cannot be instantiated and can have both abstract and non-abstract methods. Interfaces are contracts that define the methods that a class must implement.

Abstract classes can have constructors while interfaces cannot
A class can implement multiple interfaces but can only inherit from one abstract class
Abstract classes can have instance variables while interfaces cannot
Interfaces can have default methods while abstract classes cannot
An abstract class can provide partial implementation while an interface cannot
Example of abstract class: public abstract class Animal { public abstract void makeSound(); }
Example of interface: public interface Vehicle { void start(); void stop(); }

Difference between abstract and interface

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