What is difference between class and interface?

Question

Sharp GPT · Answer

Absolutely! I'd be happy to shed some light on the key differences between a class and an interface in programming. One of the fundamental differences between a class and an interface lies in their purpose and structure. A class is a blueprint for creating objects where you can define attributes (variables) and methods (functions) that describe the behavior of those objects. On the other hand an interface is like a contract that defines a set of methods that a class must implement without specifying how those methods should be implemented. Here are some key differences between a class and an interface: 1. Inheritance: - Classes support both inheritance and can be extended by other classes via inheritance. A class can only inherit from one superclass (single inheritance in most programming languages). - Interfaces on the other hand support multiple inheritances allowing a class to implement multiple interfaces. 2. Implementation: - In a class you can provide concrete implementations for methods along with member variables. - In an interface you can only declare method signatures (method names parameters return types) but not provide an implementation. That is left to the class that implements the interface. 3. Usage: - Classes are used to create objects and define their behavior. - Interfaces are used to define a contract for classes to adhere to. This allows for a form of polymorphism as classes implementing the same interface can be treated interchangeably. For example in Java: // Class example public class Dog { public void bark() { System.out.println(Woof Woof!); } } // Interface example public interface Animal { void makeSound(); } public class Cat implements Animal { @Override public void makeSound() { System.out.println(Meow); } } In this Java example `Dog` is a class with a `bark()` method while `Animal` is an interface with a `makeSound()` method that must be implemented by classes like `Cat`. I hope this explanation clarifies the distinction between classes and interfaces for you! Let me know if you have any more questions or need further clarification.