reading-notes

Inheritance and Interfaces

Interfaces:

• blueprint of a class. It has static constants and abstract methods.
• can be only abstract methods in the Java interface, not method body.
• can contain only constants, method signatures, default methods, static methods, and nested types.
• can only be implemented by classes or extended by other interfaces.
• once the interface is defined; any number of classes can be implemented and the class can implement any number of interfaces unlike the inheritance.

benefits of Interfaces:

1. It is used to achieve abstraction.
2. By interface, we can support the functionality of multiple inheritance.
3. It can be used to achieve loose coupling.

Syntax:

interface <interface_name>{  
      
    // declare constant fields  
    // declare methods that abstract   
    // by default.  
}  

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Inheritance:

• one object acquires all the properties and behaviors of a parent object.

• we can create new classes that are built upon existing classes:
• reuse methods and fields of the parent class.
• add new methods and fields in your current class.

benefits of inheritance:

1. Method Overriding.
2. Code Reusability.

syntax :

class Subclass-name extends Superclass-name  
{  
   //methods and fields  
}