What is Object-Oriented Programming in Java and its key features?
This question checks your foundational knowledge of OOP principles within the context of Java. It focuses on encapsulation, inheritance, polymorphism, and abstraction.
Why Interviewers Ask This
Java is widely used at Google, so understanding OOP is essential for writing clean, maintainable code. Interviewers want to ensure you can leverage these principles to create modular and extensible software architectures. It also reveals your ability to think in terms of objects and relationships.
How to Answer This Question
Define OOP briefly and list the four main pillars: encapsulation, inheritance, polymorphism, and abstraction. Provide a simple example for each concept using Java syntax. Explain how these features improve code reusability and reduce complexity. Mention interfaces and abstract classes as tools for achieving abstraction.
Key Points to Cover
- Encapsulation for data hiding
- Inheritance for code reuse
- Polymorphism for flexibility
- Abstraction for simplicity
Sample Answer
Object-Oriented Programming in Java organizes code around objects rather than functions. Encapsulation hides internal state and requires interaction through methods. Inheritance allows classes to inherit properties from…
Common Mistakes to Avoid
- Providing vague definitions without examples
- Confusing composition with inheritance
- Forgetting to mention interfaces
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