What is OOPs concept in Java? Explain what Inheritance is, polymorphism, encapsulation and abstraction? What is default key word? Explain collection details? You can get more from interview question online.

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OOPs concept in Java includes Inheritance, polymorphism, encapsulation, and abstraction. Default keyword is used in Java for default values. Collections in Java are used to store and manipulate groups of objects.

Inheritance allows a class to inherit properties and behavior from another class. Example: class B extends class A.
Polymorphism allows objects to be treated as instances of their parent class. Example: Animal class can have subclasses like Dog and Cat.
Encapsulation is the concept of bundling data and methods that operate on the data into a single unit. Example: private variables with public getter and setter methods.
Abstraction is the concept of hiding the implementation details and showing only the necessary features of an object. Example: abstract class or interface in Java.
Default keyword in Java is used to provide default values for variables. Example: int num = 0; is equivalent to int num = default;
Collections in Java are used to store and manipulate groups of objects. Examples include ArrayList, LinkedList, HashMap, etc.

What is OOPs concept in Java? Explain what Inheritance is, polymorphism, encapsulation and abstraction? What is default key word? Explain collection details? You can get more from interview question online.

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