What happens when you call Clear() on a Dictionary?

The correct answer is B: All key-value pairs are removed, capacity unchanged. Clear() removes all elements but doesn't deallocate capacity. The dictionary remains usable with count=0.

Which namespace is required to use Console.WriteLine() in C#?

The correct answer is B: System. Console class is part of the System namespace. You need to include 'using System;' at the beginning of your code to use Console.WriteLine().

Which of the following is NOT a built-in state management technique in ASP.NET?

The correct answer is D: Block State. ViewState, Session State, Application State, and Cookies are valid state management techniques. Block State is not a standard ASP.NET technique.

What happens when a derived class constructor does not explicitly call the base class constructor in C#?

The correct answer is B: Parameterless base constructor is called automatically. C# automatically calls the parameterless constructor of the base class if no explicit base() call is made, ensuring base class initialization.

In a competitive exam scenario, if you need both fast lookup and sorted iteration, which should you choose?

The correct answer is B: SortedDictionary. SortedDictionary provides O(log n) lookup and maintains sorted order during iteration. Alternatives are slower or require post-processing.

Home

Home › Subjects › C# Programming

C# Programming

C# and .NET for campus placement

76 Q 4 Topics Take Mock Test

Difficulty: All Easy Medium Hard 41–50 of 76

Topics in C# Programming

All Basics & Syntax 100 OOP in C# 100 Collections 71 ASP.NET Basics 19

Q.41 Easy OOP in C#

What happens when you mark a class with the 'sealed' modifier?

A The class cannot have any public members

B The class cannot be inherited from

C The class cannot be instantiated

D The class cannot have virtual methods

Correct Answer: B. The class cannot be inherited from

EXPLANATION

'sealed' keyword prevents a class from being inherited. This is useful for security and performance optimization when you want to prevent further derivation.

Test

Q.42 Easy OOP in C#

What is the output of using 'nameof()' operator on a property in C#?

A Returns the property value

B Returns the property name as a string

C Returns the property type

D Returns a null reference

Correct Answer: B. Returns the property name as a string

EXPLANATION

'nameof()' operator (C# 6+) returns the name of a variable, type, or member as a string literal, useful for logging and validation.

Test

Q.43 Easy OOP in C#

Which access modifier allows a member to be accessed only within the same assembly?

A private

B internal

C protected internal

D public

Correct Answer: B. internal

EXPLANATION

'internal' access modifier restricts member access to the same assembly only. This is useful for creating assembly-wide internal APIs.

Test

Q.44 Easy OOP in C#

Which of the following correctly demonstrates an abstract class with an abstract method in C#?

A public abstract class Base { public abstract void Method(); }

B public class Base { public abstract void Method(); }

C public abstract class Base { public void Method(); }

D public sealed abstract class Base { public abstract void Method(); }

Correct Answer: A. public abstract class Base { public abstract void Method(); }

EXPLANATION

An abstract class uses the 'abstract' keyword, and abstract methods must be declared without implementation inside abstract classes.

Test

Q.45 Easy OOP in C#

In C#, can a class inherit from multiple classes?

A Yes, always

B No, C# does not support multiple inheritance

C Yes, but only if they are abstract

D Yes, using the 'multiple' keyword

Correct Answer: B. No, C# does not support multiple inheritance

EXPLANATION

C# does not support multiple class inheritance to avoid the diamond problem. However, a class can implement multiple interfaces.

Test

Q.46 Easy OOP in C#

Which keyword is used to create a derived class in C#?

A extends

B inherits

C :

D ->

Correct Answer: C. :

EXPLANATION

In C#, the colon (:) is used to indicate inheritance. For example, 'class Child : Parent' creates a derived class.

Test

Q.47 Easy OOP in C#

In C#, what is the default access modifier for class members?

A public

B private

C protected

D internal

Correct Answer: B. private

EXPLANATION

The default access modifier for class members in C# is 'private', which restricts access to within the class only.

Test

Q.48 Easy Basics & Syntax

Which of the following is a correct way to declare a property with auto-implementation in C#?

A public int Age { get; set; }

B public int Age() { get; set; }

C public Age int { get; set; }

D public int get Age; set;

Correct Answer: A. public int Age { get; set; }

EXPLANATION

Auto-implemented properties in C# use the syntax: public Type PropertyName { get; set; } without explicitly defining the backing field.

Test

Q.49 Easy Basics & Syntax

Consider this code: int[] arr = new int[5]; foreach(var item in arr) { Console.Write(item + " "); } What is the output?

A Nothing (empty output)

B 0 0 0 0 0

C Throws an IndexOutOfRangeException

D Null Null Null Null Null

Correct Answer: B. 0 0 0 0 0

EXPLANATION

Arrays in C# are automatically initialized with default values. For int arrays, the default value is 0. Therefore, the output will be five zeros separated by spaces.

Test

Q.50 Easy Basics & Syntax

Which collection type in C# is best suited for key-value pair storage with unique keys?

A List

B Dictionary

C HashSet

D Queue

Correct Answer: B. Dictionary

EXPLANATION

Dictionary<K, V> stores key-value pairs and ensures unique keys. List stores ordered values, HashSet stores unique values only, Queue is FIFO.

Test

1…3 4 5 6 7 8

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

C# Programming