Dotnet framework is a software development framework provide predefined function so it is easy to use. It includes a library and runtime environment. FCL (Framework Class Library) provides user interface, database connectivity, cryptography, web development and many more. .NET programs are executed in CLR (Common Language Runtime). Provide language interoperability i.e., provides many languages which combine altogether.
Object-oriented programming Language independence Efficient data access Code Sharing Support for services
It is done in two parts
1. Language compilers – compiler time process
2. JIT – runtime process
Compiler time process
The .NET framework has one or more language compilers in which source code(ex: abc.exe file) is compiled by respective compiler(converted to abc.EXE) and translate source code into MSIL code (it also contains meta data) usually EXE and DLL (Dynamic Link Libraries) file.
Runtime Process
CLR includes a JIT compiler for converting MSIL code into native code and that is then executed by OS.
Delegates
- It is a reference type.
- It is a function pointer or it holds a reference (pointer) to a function (method).
- It is type safe.
- Delegates are mainly used for the event handling and the callback methods. Also, note this method has the same signature as that of the EligibleToPromotion delegate. This is very important because the Promote method cannot be passed as a parameter to the delegate if the signature differs. This is the reason why delegates are called type-safe function pointers.
{
//include class libraries/namespace
using System;
//declare namespace
namespace namespaceName
{
//class declaration
class className
{
//Data Members
int something;
float a;
//Method/functions/block
public void DoSomething()
{
//implementation
}
}
}
} Understanding the Object Class in C#: The Object class is the Superclass of all dot net types. That means, all the types in .NET Framework are inherited directly or indirectly from the Object class. Because of this inheritance, every type in .NET inherits the ToString() method from the Object class. If you go to the definition of Object class, then you will see that the ToString() method is defined as a Virtual Method which allows this method to be overridden in the child classes
Every type in .NET is implicitly inherited from the Object class and hence all the public and protected members of the object class (excluding private members) are inherited into the child class and by using the child class object we can access all the public and protected members of the object class in C#. For example, int is a primitive type and string a reference type and both of these two types are inherited from the Object class, and hence using the variable of int and string type, we can access all the public and protected members of the object class.
In other words, we can say that each and every class type (Reference Types) or struct type (Value Types) are directly or indirectly implicitly inherited from the Object class in C#. Therefore, every object in C# gets the ToString method, which returns a string representation of that object. So, the ToString() method returns a string that represents the current object.
For example, all variables of type int or float have the ToString method, which enables them to return their contents as a string. For a better understanding, please have a look at the following example. In the above example, the Number is an integer type variable and when we invoke the ToString() method on the Number object, it will give us the string representation of the integer 100.
Overriding the ToString() Method in C#: The point that you need to remember is the ToString method is defined as a Virtual Method inside the Object class and our custom Employee class is implicitly inherited from the Object class, and hence within this Employee class, we need to override the ToString method by using the override modifier.
What is Equals Method in C#? The Equals is a virtual method defined in the Object class and this method is available to all the .NET Types as Object is the superclass of all .NET Types.
What is Equals Method in C#?
As Equals is a virtual method, we can also override this method under our classes. The following is the signature of this method.
public virtual bool Equals(object obj): This method is used to determine whether the specified object is equal to the current object. Here, the parameter obj specifies the object to compare with the current object. It returns true if the specified object is equal to the current object; otherwise, false. Before understanding how to override and when to override, let us first understand what is the difference between the == Operator and Equals method in C#.
Difference Between the “==” Operator and the Equals() Method in C#: As we already discussed every type in .NET, directly or indirectly inherits from the Object class. So, the Equals() virtual method, which has a default implementation within the Object class is also available in every .NET (Primitive as well as Reference) type via inheritance.
Equals method and == Operator with Enum Type in C#: In the following example, we compare 2 enums, and both the == operator and Equals() method return true since both direction1 and direction2 enums have the same underlying integer value i.e. 1. Ang again, Enums are value type and they hold the value instead of the reference address.
Equals method and == Operator with Reference Type in C#: If the type is a reference type, then by default both the == operator and Equals method check for reference equality whereas we can change this default behavior of the Equals() method by overriding it to check for value equality. If this is not clear at the moment, don’t worry let us understand this with an example,
In the following example, C1 and C2 are 2 different object reference variables of the Customer class. But both are pointing to the same object. The most important point that you need to keep in mind is reference variables are different from objects. Reference variables are created on the stack memory and they point to the actual objects which are stored in the heap memory.
Since, C1 and C2 both refer to the same object, the reference equality, and the value equality is true. Value equality means that two objects contain the same values. In this example, the actual object is only one, so obviously, the values are also equal. If two objects have reference equality, then they also have value equality, but value equality does not guarantee reference equality.
Overriding the Equals Method of the Object Class in C#: we override the Equals() method of the Object class inside the Customer class. When overriding the Equals() method, make sure the passed object is not null and can be cast to the type you are comparing. When overriding Equals(), you also need to override GetHashCode(), otherwise you will get a compiler warning.
Convert.ToString and ToString Method in C# Both these methods are used to convert a value to a string. The difference is Convert.ToString() method handles null whereas the ToString() doesn’t handle null in C#.
In C# if you declare a string variable and if you don’t assign any value to that variable, then by default that variable takes a null value. In such a case, if you use the ToString() method then your program will throw the Null Reference Exception. On the other hand, if you use the Convert.ToString() method then your program will not throw an exception.
Why do we need Checked and Unchecked Keywords in C#? According to MSDN, The Checked Keyword in C# is used to explicitly enable overflow checking for integral-type arithmetic operations and conversions. The Unchecked Keyword in C# is used to suppress overflow-checking for integral-type arithmetic operations and conversions.
Here, overflow checking means when the value of any integral type exceeds its range, it does not raise any exception, instead it will give us unexpected or garbage results. If this is not clear at the moment, then don’t worry we will try to understand the above two points with examples.
C#.NET is a completely Object-Oriented Programming Language. It means it supports all 4 OOPs Principles i.e. Abstraction, Encapsulation, Inheritance, and Polymorphism.
Class and Objects in C#
Constructors in C# Types of Constructors in C# Why We Need Constructors in C# Static vs Non-Static Constructors in C# Private Constructors in C# Destructors in C# Garbage Collection in C#.NET Access Specifiers in C# Encapsulation in C# Abstraction in C# Inheritance in C# Types of Inheritance in C# How to use Inheritance in Application Development IsA and HasA Relationship in C# Generalization and Specialization in C# Abstract Class and Abstract Methods in C# Abstract Class and Abstract Methods Interview Questions in C# How to Use Abstract Classes and Methods in C# Application Interface in C# Interface Interview Questions and Answers in C# Interface Realtime Examples in C# Multiple Inheritance in C# Multiple Inheritance Realtime Example in C# Polymorphism in C# Method Overloading in C# Operator Overloading in C# Method Overriding in C# Method Hiding in C# Partial Class and Partial Methods in C# Sealed Class and Sealed Methods in C# Extension Methods in C# Static Class in C# Variable Reference and Instance of a Class in C#
Chapter-4 Exception Handling Exception Handling in C# Multiple Catch Blocks and Finally Block in C# Custom Exception in C# Inner Exception in C# Exception Handling Abuse in C#
Chapter-5 Events, Delegates, and Lambda Expression in C# Course Structure of Events, Delegates, and Lambda Expression Roles of Events, Delegates, and Event Handler in C# Delegates in C# Multicast Delegates in C# Delegates Real-Time Example in C# Generic Delegates in C# Anonymous Method in C# Anonymous Method Realtime Example in C# Lambda Expressions in C# Events in C# with Examples
Chapter-6 MultiThreading Multithreading in C# Constructors of Thread class in C# How to Pass Data to Thread Function in Type-Safe Manner in C# How to Retrieve Data from a Thread Function in C# IsAlive Property and Join Method of Thread Class in C# Thread Synchronization in C# Locking in C# Monitor Class in C# Mutex Class in C# Semaphore Class in C# SemaphoreSlim Class in C# Deadlock in C# Performance Testing of a Multithreaded Application Thread Pooling in C# Foreground and Background Threads in C# AutoResetEvent and ManualResetEvent in C# Thread Life Cycle in C# Threads Priorities in C# How to Terminate a Thread in C# Inter Thread Communication in C# How to Debug a Multi-threaded Application in C#
Chapter-7 Reflection C# Reflection Dynamic Type in C# Var Keyword in C# Dynamic vs Var Keyword in C# Dynamic vs Reflection in C# Volatile Keyword in C#
Chapter-8 File Handling in C# File Handling in C# FileStream Class in C# StreamReader and StreamWriter in C# File Class in C# TextWriter and TextReader in C# BinaryWriter and BinaryReader in C# StringWriter and StringReader in C# FileInfo Class in C# DirectoryInfo Class in C#
Chapter-9 Collections in C# Arrays in C# 2d Array in C# Advantages and Disadvantages of Arrays in C# Collections in C# Non-Generic ArrayList in C# Non-Generic Hashtable in C# Non-Generic Stack in C# Non-Generic Queue in C# Non-Generic SortedList in C# Advantages and Disadvantages of Non-Generic Collection in C# Generic Collections in C# Generics in C# Generic Constraints in C# Generic List Collection in C# How to Sort a List of Complex Types in C# Comparison Delegate in C# Generic Dictionary Collection Class in C# Conversion Between Array List and Dictionary in C# List vs Dictionary in C# Generic Stack Collection Class in C# Generic Queue Collection Class in C# Foreach Loop in C# Generic HashSet Collection Class in C# Generic SortedList Collection Class in C# Generic SortedSet Collection Class in C# Generic SortedDictionary Collection Class in C# Generic LinkedList Collection Class in C# Concurrent Collection in C# ConcurrentDictionary Collection Class in C# ConcurrentQueue Collection Class in C# ConcurrentStack Collection Class in C# ConcurrentBag Collection Class in C# BlockingCollection Class in C# Chapter-10 Asynchronous Programming Introduction to Asynchronous Programming Async and Await Operators in C# Tasks in C# How to Return a Value from Task in C# How to Execute Multiple Tasks in C# How to Limit Number of Concurrent Tasks in C# How to Cancel a Task in C# using Cancellation Token How to Create Synchronous Method using Task in C# Retry Pattern in C# Only One Pattern in C# How to Control the Result of a Task in C# Task-based Asynchronous Programming in C# Chaining Tasks by Using Continuation Tasks ValueTask in C# How to Cancel a Non-Cancellable Task in C# Asynchronous Streams in C# How to Cancel Asynchronous Stream in C#
Chapter-11 Parallel Programming Task Parallel Library in C# Parallel For in C# Parallel Foreach Loop in C# Parallel Invoke in C# Maximum Degree of Parallelism in C# How to Cancel Parallel Operations in C# Atomic Methods Thread Safety and Race Conditions in C# Interlocked vs Lock in C# Parallel LINQ in C#
Chapter-12 AutoMapper AutoMapper in C# AutoMapper Complex Mapping in C# Mapping Complex type to Primitive Type using AutoMapper in C# AutoMapper ReverseMap in C# AutoMapper Conditional Mapping in C# AutoMapper Ignore Property in C# UseValue ResolveUsing and Null Substitution in AutoMapper
Chapter-13 Optional Parameter, Indexers, and Enums How to make Optional Parameters in C# Indexers in C# Indexers Real-Time Example in C# Enums in C#
Chapter-14 ADO.NET (Working with Database) Introduction to ADO.NET ADO.NET using SQL Server ADO.NET SqlConnection ADO.NET SqlCommand ADO.NET SqlDataReader ADO.NET SqlDataAdapter ADO.NET DataTable in C# DataTable Methods in C# ADO.NET DataSet DataSet using SQL Server The Architecture of DataSet in .NET ADO.NET Using Stored Procedure Transactions in ADO.NET ADO.NET Connection Pooling ADO.NET Architecture
Chapter-15 .NET Framework Architecture Introduction to .NET Framework Common Language Runtime in .NET .NET Program Execution Process Intermediate Language (ILDASM & ILASM) Code in C# Common Type System in .NET Framework Common Language Specification in .NET Framework Managed and Unmanaged Code in .NET Assembly DLL EXE in .NET Framework App Domain in .NET Framework Strong and Weak Assemblies in .NET What is delayed signing? Can we see a simple example of GAC & How to handle multiple versions in GAC (Binding redirect)?
Chapter-16 C# 7 New Features C# 7 New Features Out Variables in C# Pattern Matching in C# Digit Separators in C# Tuples in C# Splitting Tuples in C# Local Functions in C# Ref Returns and Ref Locals in C# Generalized Async Return Types in C# Expression Bodied Members in C# Thrown Expression in C# Async Main in C# Chapter-17 C# 8 Features
C# 8 New Features ReadOnly Structs in C# Default Interface Methods in C# Pattern Matching in C# Using Declarations in C# Static Local Functions in C# Disposable Ref Structs in C# Nullable Reference Types in C# Asynchronous Streams in C# Asynchronous Disposable in C# Indices and Ranges in C# Null-Coalescing Assignment Operator in C# Unmanaged Constructed Types in C# Stackalloc in Nested Expressions in C#
Chapter-18 C# 9 Features Top-Level Statements Record Types Init-Only Setters Enhancements to Pattern Matching Natural-Sized Integers Function Pointers Target Type New Target Type Conditional Static Anonymous Methods Covariant Return Types Lambda Discard Parameters Attributes of Local Functions
Chapter-19 C# 10 Features Record Structs Improvements in Structure Types Interpolated String Handlers Global using Directives File-scoped namespace declaration Extended property patterns Improvements in lambda expressions Allow const interpolated strings Record types can seal ToString() Improved definite assignment Allow both assignment and declaration in the same deconstruction Allow AsyncMethodBuilder attribute on methods CallerArgumentExpression attribute Enhanced #line pragma Chapter 20 Working with XML and JSON Chapter-21 Entity Framework (You will know Everything about EF) Database First Approach Code First Approach
Chapter-22 Language Integrated Query (LINQ) Architecture of LINQ Different Ways to Write LINQ Query IEnumerable and IQueryable in C# Differences between IEnumerable and IQueryable LINQ Extension Methods LINQ Operators LINQ Select Operator in C# LINQ SelectMany in C# Where Filtering Operators in LINQ OfType Operator in LINQ Set Operators in LINQ LINQ Distinct Method in C# LINQ Except in C# LINQ Intersect Method in C# LINQ Union in C# Linq Concat Method in C# Ordering Operators in LINQ Linq OrderBy Method in C# Linq OrderByDescending Method in C# Linq ThenBy and ThenByDescending Method in C# LINQ Reverse Method in C# LINQ Aggregate Functions in C# Linq Sum in C# Linq Max in C# Linq Min Method in C# Linq Average Method in C# Linq Count Method in C# Linq Aggregate Method in C# LINQ Quantifiers Operators Linq All Operator in C# Linq Any in C# Linq Contains in C# Linq GroupBy in C# GroupBy By Multiple Keys in Linq Linq ToLookup Method in C# Linq Joins in C# Linq Inner Join in C# Linq Join with Multiple Data Sources Linq Group Join in C# Left Join in Linq Linq Cross Join Element Operators in LINQ ElementAt and ElementAtOrDefault in Linq First and FirstOrDefault Methods in Linq Last and LastOrDefault Methods in Linq Single and SingleOrDefault Methods in Linq DefaultIfEmpty Method in Linq SequenceEqual Operator in LINQ Partitioning Operators in Linq Take Operator in Linq TakeWhile Method in Linq Skip Method in Linq SkipWhile Method in Linq Paging Using Skip and Take Method Linq Range Method in C# Linq Repeat Method in C# Linq Empty Method in C# Linq Append Method in C# Linq Prepend Method in C# Linq Zip Method in C# Deferred Execution vs Immediate Execution in LINQ ToList and ToArray Methods ToDictionary Method Cast Operator Difference between Cast and OfType Operators
Chapter-23 Design Patterns Chapter -23-A Creational Design Pattern Creational Design Pattern in C# Factory Design Pattern in C# Factory Method Design Pattern in C# Abstract Factory Design Pattern in C# Builder Design Pattern in C# Builder Design Pattern Real-time Example Fluent Interface Design Pattern in C# Prototype Design Pattern in C# Shallow Copy and Deep Copy in C# Singleton Design Pattern in C# Why Singleton Class sealed in C# Thread-safe Singleton Design Pattern in C# Lazy Loading and Eager Loading in Singleton Design Pattern Singleton VS Static class in C# Singleton Design Pattern Real-Time Examples in C#
Chapter-23-B Structural Design Pattern Structural Design Pattern in C# Adapter Design Pattern in C# Adapter Design Pattern Real-time Example Facade Design Pattern in C# Decorator Design Pattern in C# Decorator Design Pattern Real-Time Example Bridge Design Pattern in C# Bridge Design Pattern Real-Time Example Composite Design Pattern in C# Proxy Design Pattern in C# Proxy Design Pattern Real-time Example Flyweight Design Pattern in C#
Chapter-23-C Behavioral Design Pattern Behavioral Design Pattern in C# Iterator Design Pattern in C# Observer Design Pattern in C# Chain of Responsibility Design Pattern in C# Real-Time Examples of Chain of Responsibility Design Pattern State Design Pattern in C# State Design Pattern Real-time Example Template Method Design Pattern in C# Template Method Design Pattern Real-time Example Command Design Pattern in C# Visitor Design Pattern in C# Strategy Design Pattern in C# Strategy Design Pattern Real-Time Example – Travel Strategy Pattern Real-Time Example – Payment Interpreter Design Pattern in C# Mediator Design Pattern in C# Memento Design Pattern in C#
Chapter-23-D Dependency Injection Design Pattern Dependency Injection Design Pattern in C# Property and Method Dependency Injection in C# Dependency Injection using Unity Container in MVC Chapter-23-E Repository Design Pattern Repository Design Pattern in C# Generic Repository Pattern in C# Using Both Generic and Non-Generic Repository Patterns in C# Unit Of Work in Repository Pattern
Chapter-24 SOLID Design Principles Single Responsibility Principle in C# Open-Closed Principle in C# Liskov Substitution Principle in C# Interface Segregation Principle in C# Dependency Inversion Principle in C#
Chapter-25 Experienced Interview Questions: What is the IDisposable interface & finalize Dispose of Pattern in GC? What are different .NET data types and their uses according to scenarios? Explain TypeSafe, Casting, Explicit casting, and Implicit casting. What do you mean by Covariance & Contravariance in .NET 4.0? What are boxing and unboxing? What is Optimistic and Pessimistic Locking? What are regular expressions & can we see some practical demonstrations? .NET 4.5 feature – Why do we need REGEX timeout? Tips to improve your C# Debugging. Can you explain Named Parameters, Ref, Out, Volatile & Parsetry? What is the difference between Const & ReadOnly? Explain the difference between the “IS” and “AS” keywords. What is the #Debug directive? What is the difference between debugging and Release? What are serialization and deserialization? What are IComparable and IComparer? What is the use of the Yield Keyword in C#? What is a C# indexer? What are ?? (Coalescing operators)? What is C# reflection? What is the Dynamic keyword & How does it differ from Reflection? What is the difference between Early binding and Late binding? What is the difference between VAR and Dynamic keywords? What are Circular Dependencies and How to resolve them? How can we mark a method as deprecated? What is the difference between Build VS Rebuild Vs Clean? Importance of bin folder & obj folder in C#. What is Naming Convention? What is NuGet? What are portable class libraries? What are Async and Await keywords? Explain Concurrency VS Parallelism. Does Async use threads? What are ENUM and flags in ENUMS? How to convert string to ENUM? Explain NULLABLE Types. What are DataAnnotations? How to generate Random numbers in C#? Preprocessor Directives/Symbols