Sdaemon Infotech Interview Questions and Answers

Q1. What is Object Oriented Programming?
Ans. 
Object Oriented Programming is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.
• OOP focuses on creating objects that interact with each other to solve problems.

• It involves concepts like classes, objects, inheritance, polymorphism, and encapsulation.

• Example: In a banking application, you can have classes like Account, Customer, and Tr...read more
Answered by AI
Add your answer
Q2. What are the important pillars of OOPs?
Ans. 
The important pillars of OOPs are Inheritance, Encapsulation, Abstraction, and Polymorphism.
• Inheritance allows a class to inherit properties and behavior from another class.

• Encapsulation hides the internal state of an object and only exposes necessary information.

• Abstraction focuses on the essential features of an object while hiding the implementation details.

• Polymorphism allows objects to be treated as instances of t...read more
Answered by AI
Add your answer
Q3. What is Encapsulation? How do you hide data using Encapsulation?
Ans. 
Encapsulation is the concept of bundling data and methods that operate on the data within a single unit.
• Encapsulation helps in hiding the internal state of an object and restricting access to it.

• Data hiding is achieved by making the variables private and providing public methods to access or modify them.

• For example, a class 'Car' may have private variables like 'model' and 'year' with public methods like 'getModel()' a...read more
Answered by AI
Add your answer
Q4. What is Inheritance?
Ans. 
Inheritance is a concept in object-oriented programming where a class inherits properties and behaviors from another class.
• Allows a class to inherit attributes and methods from another class

• Promotes code reusability and reduces redundancy

• Creates a parent-child relationship between classes

• Derived class can access public and protected members of the base class

• Example: Class Car inherits from class Vehicle
Answered by AI
Add your answer
Q5. What is Polymorphism?
Ans. 
Polymorphism is the ability of a single function or method to operate on different data types.
• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example: Inheritance allows a child class to override a method of its parent class, exhibiting polymorphic behavior.
Answered by AI
Add your answer
Q6. What is Abstract Class?
Ans. 
Abstract class is a class that cannot be instantiated and may contain abstract methods.
• Cannot be instantiated directly

• May contain abstract methods that must be implemented by derived classes

• Can have both abstract and non-abstract methods
Answered by AI
Add your answer
Q7. What is difference between Abstract Class and Interface?
Ans. 
Abstract class can have implementation details while interface cannot. Class can implement multiple interfaces but only inherit from one abstract class.
• Abstract class can have method implementations while interface cannot.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Interfaces are used to define a contract for classes to implement, while abstract classes are used to provide a c...read more
Answered by AI
Add your answer
Q8. What is Layout page in MVC?
Ans. 
Layout page in MVC is a shared template that defines the structure of the final output HTML.
• Layout page contains common elements like header, footer, navigation menu, etc.

• It allows for consistent design across multiple views.

• Can be used to define sections that can be overridden by individual views.
Answered by AI
Add your answer
Q9. What is primary key?
Ans. 
Primary key is a unique identifier for each record in a database table.
• Primary key ensures each record in a table is unique

• It can be a single column or a combination of columns

• Primary key constraints prevent duplicate or null values
Answered by AI
Add your answer
Q10. What is Unique key?
Ans. 
Unique key is a column or a set of columns that uniquely identifies each row in a table.
• A unique key constraint ensures that all values in a column or a set of columns are unique.

• It can be used to enforce data integrity and prevent duplicate entries.

• Example: Employee ID in an employee table can be a unique key.
Answered by AI
Add your answer
Q11. Can a table have multiple primary key?
Ans. 
Yes, a table can have multiple primary keys.
• A table can have a composite primary key, which consists of multiple columns.

• Each column in the composite primary key contributes to uniquely identifying each row.

• Example: CREATE TABLE Employee (emp_id INT, dept_id INT, PRIMARY KEY (emp_id, dept_id));
Answered by AI
Add your answer
Q12. Query for finding ID, Name for employee with Maximum Salary
Ans. 
Query to find ID and Name of employee with maximum salary
• Use SQL query with MAX() function to find the maximum salary

• Join the result with employee table to get ID and Name
Answered by AI
Add your answer
Q13. Select ID,Name from Employee where Salary = { Selelct Max(Salary) from Employee};
Ans. 
The query selects the ID and Name of the employee with the highest salary.
• The query uses a subquery to find the maximum salary in the Employee table.

• The outer query then selects the ID and Name of the employee with that maximum salary.
Answered by AI
Add your answer
Q14. If you have static constructor and default constructor, which gets executed first?
Ans. 
Static constructor gets executed first before default constructor.
• Static constructor is called only once, when the class is first accessed or instantiated.

• Default constructor is called every time a new instance of the class is created.

• Example: If a class has both static and default constructors, the static constructor will be executed before the default constructor.
Answered by AI
Add your answer
Q15. Can static constructor have multiple arguments?
Ans. 
No, static constructors cannot have multiple arguments.
• Static constructors in C# do not take any arguments.

• They are used to initialize static data members or perform any necessary setup for the class.

• Example: public static MyClass() { // constructor code }
Answered by AI
Add your answer
Q16. If you have class and private variable. Can you use that class in other class?
Ans. 
Yes, by using access modifiers like public or internal.
• Yes, by changing the access modifier of the class to public or internal.

• Private variables can be accessed within the same class but not outside. Use properties or methods to access them in other classes.

• Example: class A has a private variable 'x'. In class B, create an instance of class A and access 'x' using a public method or property.
Answered by AI
Add your answer

Create a form and do CRUD Operation