OOPs Questions for Capgemini Interview

Introduction

• Presenter: Anishul from Tech and Diary channel.
• Focus of the video: Discussing OOPS (Object-Oriented Programming) questions commonly asked in Capgemini interviews.
• Previous videos on the channel cover:
  • Technical interview questions (DBMS, SQL queries)
  • Interview experiences from students (VIT and Galgottia universities).
  • Daily job and internship updates.

Key Features of OOPs

1. Definition of OOPS

   • OOPS is a programming model organized around objects instead of processes.
   • Emphasizes communication between objects rather than a series of processes.
   • Provides security through encapsulation of object members.

2. Four Key Features of OOPs:

   • Inheritance: Code reuse.
     • Be prepared to explain what inheritance means if asked.
   • Abstraction: Enhances modularity, maintenance, and agility.
     • Understand the concept of abstraction with real-life examples.
   • Encapsulation: Provides security and protection (e.g., use of private access specifier).
   • Polymorphism: Allows flexibility and interfacing.
     • Important to discuss, especially in Capgemini interviews.

Common Interview Questions

1. What is Polymorphism in Java?

   • Definition: Occurs in several different forms.
   • Two types:
     • Static Polymorphism: Resolved at compile time (via function overloading).
     • Dynamic Polymorphism: Resolved at runtime (via method overriding).

2. Difference between Abstract Class and Interface

   • Abstract classes can have both abstract and concrete methods, while interfaces can only have abstract methods.
   • A class can extend a single abstract class but can implement multiple interfaces.

3. Methods of Object Class

   • Important methods to remember:
     • clone(): Creates a copy of the object.
     • equals(): Checks equality with another object.
     • finalize(): Called by the garbage collector.
     • getClass(): Returns runtime class of the object.
     • hashCode(): Returns a hash code value for the object.
   • Remember at least 3 of these methods.

4. Access Specifiers for Top-Level Classes

   • Options: Public or default.
   • Answer: Can be public or default.

5. What is an Immutable Class?

   • A class that creates objects that cannot be changed after initialization.

6. Use of Synchronized Block

   • Achieves mutual exclusion: Ensures a code segment is executed by only one thread at a time.
   • Lock needs to be retrieved before executing the segment and released afterward.

Resources for Further Study

• Recommended site: Java T Point for detailed explanations and real-life examples of OOP concepts.

Conclusion

• Best wishes to all interviewees.
• Questions or doubts can be asked in the comments section.
• Upcoming videos will cover new tech updates.