1. What is the difference between procedural and object-oriented programming?
Procedural programming is a linear approach where code is written as a sequence of instructions, while object-oriented programming focuses on creating reusable code modules called objects.

2. What is a variable?
A variable is a named memory location that stores a value which can be accessed and manipulated by the program.

3. Define data types in programming.
Data types specify the kind of values that can be stored and manipulated in a programming language. Examples include integers, floats, booleans, and strings.

4. What is a loop?
A loop is a control structure that allows the repeated execution of a block of code until a certain condition is met.

5. Explain the concept of conditional statements.
Conditional statements are used to perform different actions based on different conditions. They allow the program to make decisions and take different paths based on these conditions.

6. What is the purpose of functions in programming?
Functions are reusable blocks of code that perform a specific task. They help in organizing code, promoting code reusability, and improving maintainability.

7. Differentiate between compile-time and runtime errors.
Compile-time errors occur during the compilation phase and prevent the program from successfully compiling. Runtime errors occur during program execution and can cause the program to terminate abruptly or display unexpected behavior.

8. Explain the concept of recursion.
Recursion is a programming technique where a function calls itself to solve a problem. It allows for elegant and concise solutions to certain types of problems.

9. What is the difference between an array and a linked list?
An array is a contiguous block of memory that stores a fixed-size collection of elements, while a linked list is a data structure where each element contains a reference to the next element in the list.

10. What is the difference between local and global variables?
Local variables are defined within a specific block or function and can only be accessed within that scope. Global variables, on the other hand, are defined outside of any specific block or function and can be accessed throughout the program.

11. Explain the concept of polymorphism.
Polymorphism is the ability of an object to take on many forms. In object-oriented programming, it allows objects of different classes to be treated as objects of a common superclass.

12. What is the purpose of an interface in programming?
An interface defines a contract for classes to follow. It specifies a set of methods that a class must implement, allowing for consistency and interoperability between classes.

13. Define the term ‘algorithm’.
An algorithm is a step-by-step procedure or a set of rules for solving a specific problem. It serves as a blueprint for solving problems and is an essential part of programming.

14. What is the difference between a stack and a queue?
A stack is a data structure that follows the Last-In-First-Out (LIFO) principle, where the last element inserted is the first one to be removed. A queue, on the other hand, follows the First-In-First-Out (FIFO) principle, where the first element inserted is the first one to be removed.

15. Explain the concept of encapsulation.
Encapsulation is the bundling of data and methods together within a class. It allows for the control of access to the data and promotes data integrity and security.

16. What is the purpose of exception handling?
Exception handling is a mechanism to catch and handle runtime errors or exceptional situations. It allows the program to gracefully handle errors and prevent the program from crashing.

17. Differentiate between static and dynamic typing.
Static typing refers to variables being assigned a specific data type during declaration and cannot be changed later. Dynamic typing, on the other hand, allows variables to hold values of different types during runtime.

18. What is the significance of version control systems?
Version control systems track and manage changes to software code, allowing multiple developers to collaborate efficiently, revert to previous versions, and maintain code history.

19. Explain the concept of concurrency and parallelism.
Concurrency refers to the ability of a system to handle multiple tasks simultaneously, while parallelism refers to the actual execution of those tasks simultaneously using multiple processors or cores.

20. What is the purpose of testing in software development?
Testing is crucial in software development to ensure that the code functions as intended, identify and fix bugs, and verify that all requirements are met.

1. What is the difference between a shallow copy and a deep copy?
A shallow copy creates a new object and references the original object’s members. A deep copy creates a new object and copies all of the original object’s members into the new object.

2. Explain the Singleton design pattern.
The Singleton design pattern restricts the instantiation of a class to a single object. It maintains a single instance of the class and provides a global point of access to it.

3. What is polymorphism and how is it implemented in programming?
Polymorphism refers to the ability of an object to take on many forms. It is typically implemented through inheritance and method overriding. For example, a base class can define a method, and its derived classes can provide their own implementation of that method.

4. What is the difference between overloading and overriding?
Overloading refers to having multiple methods in a class with the same name but different parameters. Overriding refers to providing a different implementation of a method in a derived class, which was already defined in its base class.

5. What is the difference between an abstract class and an interface?
An abstract class can have both implemented and unimplemented methods, while an interface can only have unimplemented methods. A class can inherit from multiple interfaces, but it can only inherit from a single abstract class.

6. What is a lambda expression?
A lambda expression is an anonymous function that can be treated as a data object. It allows you to write code concisely and provide a way to pass behaviors as arguments to methods or functions.

7. What are generics in programming?
Generics allow types (classes and interfaces) to be parameterized. They provide a way to create classes, methods, and interfaces that can work on different types without having to resort to type casting.

8. What is the difference between a stack and a queue?
A stack is a data structure that follows the Last-In-First-Out (LIFO) principle, meaning the last element inserted is the first one to be removed. A queue, on the other hand, follows the First-In-First-Out (FIFO) principle, meaning the first element inserted is the first one to be removed.

9. Explain the concept of multithreading.
Multithreading is the ability of a central processing unit (CPU) to execute multiple threads concurrently. It allows a program to perform multiple tasks at the same time, improving efficiency and responsiveness.

10. What is an anonymous class?
An anonymous class is a local inner class without a name. It is declared and instantiated in a single statement, and it is primarily used when you need to define a class for a one-time use.

11. Explain the concept of garbage collection.
Garbage collection is an automatic memory management process that frees up memory by identifying and deleting objects no longer in use. It allows programmers to focus on writing code without worrying about memory deallocation.

12. What is a deadlock and how can it be prevented?
A deadlock is a situation where two or more threads cannot make progress because each is waiting for a resource held by the other. Deadlocks can be prevented by ensuring proper resource allocation, avoiding circular wait, and using synchronization constructs effectively.

13. What is the purpose of the volatile keyword?
The volatile keyword is used to indicate that a variable’s value may be modified by multiple threads. It ensures that any read or write operation on the variable is performed directly on the main memory and not on a thread’s local cache.

14. What is event-driven programming?
Event-driven programming is a programming paradigm where the flow of program execution is determined by events or user actions (such as button clicks or keyboard input) rather than following a predefined sequence of instructions.

15. Explain the concept of reflection.
Reflection is a feature in programming languages that allows a program to examine its own structure, properties, and behavior at runtime. It enables dynamic loading of classes, invoking methods, and accessing member variables.

16. What is a design pattern?
A design pattern is a reusable solution to a commonly occurring problem in software design. It provides a template for solving a particular design problem and can improve the efficiency, maintainability, and flexibility of a software system.

17. What is the purpose of an IDE (Integrated Development Environment)?
An IDE is a software application that provides programming tools, such as code editors, debuggers, and build automation, in a single integrated environment. It simplifies development tasks and enhances productivity by providing a cohesive set of features.

18. What is the difference between static and dynamic linking?
Static linking is the process of linking libraries at compile time, resulting in a standalone executable file. Dynamic linking is the process of linking libraries at runtime, allowing multiple processes to share a single copy of the library code.

19. Explain the concept of Big O notation.
Big O notation is used to describe the performance or efficiency of an algorithm. It provides an upper bound representation of how the algorithm’s running time or space requirements grow relative to the size of the input data.

20. What is the purpose of unit testing?
Unit testing is the process of testing individual units or components of a software system to ensure their correctness and reliability. It helps identify defects early in the development cycle and improves the overall quality of the software.