Quiz - C# Mastery Hub

1 When was C# first released?

1998

2000

2002

2004

2 Who designed the C# programming language?

Bill Gates

Anders Hejlsberg

James Gosling

Bjarne Stroustrup

3 Which of the following is NOT a valid use case for C#?

Desktop applications

Web applications

Mobile applications

Hardware drivers

4 What type of programming language is C#?

Procedural only

Object-oriented

Functional only

Assembly language

5 What is the entry point of a C# program?

Start()

Main()

Run()

Begin()

6 Which IDE is recommended for C# development?

Visual Studio Code

Visual Studio

IntelliJ IDEA

Eclipse

7 Which command checks if .NET SDK is installed?

dotnet --version

dotnet check

net --version

dotnet --install

8 What is the free edition of Visual Studio called?

Visual Studio Free

Visual Studio Community

Visual Studio Express

Visual Studio Basic

9 Which tool is used for version control in C# projects?

SVN

Git

Mercurial

All of the above

10 Which command creates a new console application?

dotnet create console

dotnet new console

dotnet start console

dotnet init console

11 Which data type is used for whole numbers in C#?

double

decimal

int

float

12 What is the range of the int data type in C#?

-128 to 127

-32,768 to 32,767

-2,147,483,648 to 2,147,483,647

0 to 4,294,967,295

13 Which data type is best for precise decimal calculations like money?

double

float

decimal

int

14 What does the 'var' keyword do in C#?

Creates a variable without a type

Implicitly types a variable based on the value

Makes a variable constant

Creates a global variable

15 What is a nullable type in C#?

A type that can be null

A type that cannot be null

A type that is always optional

A type with a default value of null

16 What does the % operator do in C#?

Division

Multiplication

Modulus (remainder)

Percentage

17 What is the result of 10 / 3 in C# (integer division)?

3.333

3

4

3.33

18 Which operator is used for logical AND in C#?

&

&&

and

AND

19 What is the difference between ++x and x++?

No difference

++x increments before use, x++ increments after use

x++ increments before use, ++x increments after use

They produce different results only with strings

20 Which operator is used for string concatenation?

+

&

.

,

21 What does the if statement do in C#?

Executes code based on a condition

Repeats code multiple times

Defines a new variable

Creates a new class

22 Which statement is best for multiple condition checks?

if-else if

switch

while

for

23 What does the break keyword do in a switch statement?

Continues to next case

Exits the switch block

Restarts the switch

Skips the current iteration

24 What is the ternary operator syntax in C#?

condition ? true_value : false_value

condition : true_value ? false_value

true_value ? condition : false_value

condition ? false_value : true_value

25 What does the default case do in a switch statement?

Handles all unmatched values

Handles only the first value

Exits the switch

Throws an exception

26 Which loop is best when you know how many times to iterate?

while

do-while

for

foreach

27 Which loop always executes at least once?

for

while

do-while

foreach

28 What does the continue statement do in a loop?

Exits the loop entirely

Skips the current iteration

Restarts the loop

Throws an exception

29 Which loop is specifically designed for collections?

for

while

do-while

foreach

30 What does the break statement do in a loop?

Skips the current iteration

Exits the loop entirely

Restarts the loop

Continues to the next iteration

31 What is the index of the first element in an array?

0

1

-1

Depends on the array

32 Which collection type stores key-value pairs?

List<T>

Array

Dictionary<TKey, TValue>

Queue<T>

33 What is the difference between Array and List<T>?

Arrays are dynamic, Lists are fixed

Arrays are fixed, Lists are dynamic

There is no difference

Arrays can only store strings

34 Which collection ensures all items are unique?

List<T>

HashSet<T>

Array

Dictionary<TKey, TValue>

35 What is a multidimensional array?

An array with more than one dimension

An array of arrays

A collection of arrays

A list of arrays

36 Are strings mutable or immutable in C#?

Mutable

Immutable

Both

Depends on the version

37 Which class should you use for heavy string manipulation?

String

StringBuilder

StringBuffer

StringWriter

38 What is string interpolation?

Concatenating strings with +

Embedding expressions inside strings using $

Splitting strings into parts

Converting strings to numbers

39 Which method splits a string into an array of substrings?

Split()

Substring()

IndexOf()

Replace()

40 What does the Trim() method do to a string?

Removes all spaces

Removes leading and trailing spaces

Removes only leading spaces

Removes only trailing spaces

41 What is exception handling in C#?

Ignoring errors in code

Handling runtime errors gracefully

Preventing all errors

Logging only errors

42 What is the correct order of catch blocks?

Most specific to most general

Most general to most specific

Order doesn't matter

Only one catch block is allowed

43 What is the purpose of the finally block?

To catch exceptions

To always execute code regardless of exceptions

To throw exceptions

To log errors

44 Which keyword is used to throw a custom exception?

throw

throws

raise

error

45 What does the using statement do?

Imports a namespace

Automatically disposes objects

Creates a new object

Defines a scope

46 What is a method in C#?

A block of code that performs a specific task

A variable that stores data

A type of class

A property that validates data

47 What is method overloading?

Multiple methods with the same name but different parameters

Methods with different names

Methods in different classes

Methods that return different types

48 What does the 'params' keyword do?

Makes a parameter optional

Allows a method to accept a variable number of arguments

Makes a parameter read-only

Passes parameters by reference

49 What is the difference between ref and out parameters?

ref requires initialization, out doesn't

out requires initialization, ref doesn't

They are the same

ref is for value types only

50 What is a static method?

A method that belongs to the class, not an instance

A method that belongs to an instance

A method that never changes

A method that cannot be called

51 How do you declare a nullable int in C#?

int? myInt

int myInt?

nullable int myInt

int myInt = null

52 What does the ?? operator do?

Checks if a value is null

Returns the left operand if not null, otherwise the right operand

Checks for equality

Throws an exception if null

53 What does the 'is' keyword do in pattern matching?

Checks type compatibility

Casts an object

Creates a new object

Deletes an object

54 What is pattern matching in C#?

A way to match strings

A way to test values against patterns

A way to create patterns

A way to format strings

55 What does the ??= operator do?

Assigns a value if the variable is null

Checks for null

Throws an exception

Creates a new variable

56 What does LINQ stand for?

Language Integrated Query

Language Interrogation Query

Linear Integrated Query

Language Integrated Question

57 Which LINQ method filters a collection?

Select

Where

OrderBy

GroupBy

58 Which LINQ method transforms a collection?

Where

Select

OrderBy

GroupBy

59 Which LINQ method calculates the sum of a numeric property?

Average

Sum

Count

Max

60 Which LINQ method checks if any element meets a condition?

All

Any

Contains

Exists

61 What is a delegate in C#?

A type that holds a reference to a method

A type of class

A type of variable

A type of collection

62 What is the difference between Func and Action in C#?

Func returns a value, Action doesn't

Action returns a value, Func doesn't

They are the same

Func is for strings only

63 What is an event in C#?

A way to raise notifications

A type of delegate

A type of class

A type of variable

64 What does the async keyword do?

Makes a method synchronous

Marks a method as asynchronous

Makes a method faster

Makes a method return void

65 What does the await keyword do?

Blocks the thread

Suspends execution until the awaited task completes

Creates a new thread

Cancels the operation

C# Fundamentals Quiz

1 When was C# first released?

2 Who designed the C# programming language?

3 Which of the following is NOT a valid use case for C#?

4 What type of programming language is C#?

5 What is the entry point of a C# program?

6 Which IDE is recommended for C# development?

7 Which command checks if .NET SDK is installed?

8 What is the free edition of Visual Studio called?

9 Which tool is used for version control in C# projects?

10 Which command creates a new console application?

11 Which data type is used for whole numbers in C#?

12 What is the range of the int data type in C#?

13 Which data type is best for precise decimal calculations like money?

14 What does the 'var' keyword do in C#?

15 What is a nullable type in C#?

16 What does the % operator do in C#?

17 What is the result of 10 / 3 in C# (integer division)?

18 Which operator is used for logical AND in C#?

19 What is the difference between ++x and x++?

20 Which operator is used for string concatenation?

21 What does the if statement do in C#?

22 Which statement is best for multiple condition checks?

23 What does the break keyword do in a switch statement?

24 What is the ternary operator syntax in C#?

25 What does the default case do in a switch statement?

26 Which loop is best when you know how many times to iterate?

27 Which loop always executes at least once?

28 What does the continue statement do in a loop?

29 Which loop is specifically designed for collections?

30 What does the break statement do in a loop?

31 What is the index of the first element in an array?

32 Which collection type stores key-value pairs?

33 What is the difference between Array and List<T>?

34 Which collection ensures all items are unique?

35 What is a multidimensional array?

36 Are strings mutable or immutable in C#?

37 Which class should you use for heavy string manipulation?

38 What is string interpolation?

39 Which method splits a string into an array of substrings?

40 What does the Trim() method do to a string?

41 What is exception handling in C#?

42 What is the correct order of catch blocks?

43 What is the purpose of the finally block?

44 Which keyword is used to throw a custom exception?

45 What does the using statement do?

46 What is a method in C#?

47 What is method overloading?

48 What does the 'params' keyword do?

49 What is the difference between ref and out parameters?

50 What is a static method?

51 How do you declare a nullable int in C#?

52 What does the ?? operator do?

53 What does the 'is' keyword do in pattern matching?

54 What is pattern matching in C#?

55 What does the ??= operator do?

56 What does LINQ stand for?

57 Which LINQ method filters a collection?

58 Which LINQ method transforms a collection?

59 Which LINQ method calculates the sum of a numeric property?

60 Which LINQ method checks if any element meets a condition?

61 What is a delegate in C#?

62 What is the difference between Func and Action in C#?

63 What is an event in C#?

64 What does the async keyword do?

65 What does the await keyword do?