C# Programming Aptitude Test - MCQ Questions with Answers

This post presents the C# programming aptitude test created for beginners, featuring 25 multiple-choice questions. This aptitude test covers essential aspects of C# programming, making it suitable for beginners who are testing their knowledge of the language's fundamentals.

1. What is the default value of a boolean in C#?

a) 0
b) False
c) True
d) Null

2. What does the var keyword do in C#?

a) Declares a variable of variant type
b) Declares a dynamic variable that can change type
c) Enables the compiler to infer the type of the variable at compile time
d) Declares a variable that must be assigned an integer value

3. Which keyword is used to create a class inheritance in C#?

a) extends
b) super
c) this
d) : (colon)

4. What does the ToString() method do?

a) Converts the object to a string
b) Returns the type of the object
c) Changes the object's value to "String"
d) None of the above

5. Which of these is not a loop structure in C#?

a) while
b) for
c) repeat-until
d) foreach

6. How do you handle exceptions in C#?

a) try...catch
b) try...except
c) error handling
d) throw...catch

7. What is the output of the expression 3 + 4 * 5?

a) 35
b) 23
c) 20
d) 15

8. What is the scope of a public member variable?

a) Only within the class it is declared
b) Only within the project it is declared
c) Within the class and by instances of the class
d) Available to any other code that has visibility to the class

9. What keyword is used to denote an interface in C#?

a) interface
b) Interface
c) intf
d) implements

10. Which statement is true about constructors in C#?

a) A class can have multiple constructors with the same set of arguments
b) Constructors must always return a value
c) Constructors are called to initialize an object
d) Constructors are optional in a class

11. What is a property in C#?

a) A method to access and manipulate data
b) A global variable
c) A way to control access to a field of a class
d) A constant value

12. What does the static keyword indicate?

a) The member is associated with instances of a class
b) The member belongs to the class, rather than instances of the class
c) The method can only be called in a static context
d) The method will not change any object states

13. How do you create an instance of a class named MyClass?

a) MyClass obj = new MyClass();
b) MyClass obj = MyClass();
c) new MyClass obj;
d) class obj = new MyClass();

14. What is encapsulation?

a) The inclusion of one class within another
b) The practice of keeping fields within a class private, then providing access via public methods
c) A technique used to inherit from more than one base class
d) A method to ensure that classes are well formed with respect to their interfaces

15. Which collection type automatically resizes as the amount of data changes?

a) Array
b) Hashtable
c) Queue
d) List

16. What is the purpose of the Dispose method in C#?

a) To handle exceptions
b) To exit the program
c) To release unmanaged resources
d) To remove unused variables

17. What is method overriding?

a) Changing the return type of a method in a subclass
b) Providing a new implementation of a method in a subclass that is already defined in the superclass
c) Hiding the method of the superclass
d) Calling a method from the superclass

18. What is boxing in C#?

a) Converting a struct type to an object type
b) Packaging code for deployment
c) Encrypting data for security
d) Creating a user-defined box type

19. Which keyword is used to define an abstract class?

a) abstract
b) Abstract
c) abstracted
d) AbstractClass

20. What is namespace used for in C#?

a) To organize code elements and provide control over the scope of class names
b) To package and deploy classes
c) To provide networking capabilities
d) To create storage for application data

21. What is the output of Console.WriteLine(10 == 10);?

a) 10
b) True
c) False
d) Error

22. Which of the following is not a valid way to declare an array in C#?

a) int[] array = new int[5];
b) int array[] = new int[5];
c) int[] array = {1, 2, 3, 4, 5};
d) int[] array = new int[]{1, 2, 3, 4, 5};

23. What does the virtual keyword do?

a) Declares a variable that can change types
b) Allows a method to be overridden in a derived class
c) Makes a class only inheritable virtually
d) Instantiates virtual objects

24. What is an interface in C#?

a) A class that implements all methods as virtual
b) A fully abstract class that can include both abstract methods and concrete methods
c) A type that defines a contract but does not implement the methods
d) A special form of class used for data storage

25. How do you concatenate strings in C#?

a) Using the + operator
b) Using the & operator
c) Using the concat method
d) Using the append method