C# Language
- Getting started with C# Language
- Learn Tutorial
- How to Start Learning C# While Still in College
- Awesome Book
- Awesome Community
- Awesome Course
- Awesome Tutorial
- Awesome YouTube
- .NET Compiler Platform (Roslyn)
- Access Modifiers
- Access network shared folder with username and password
- Accessing Databases
- Action Filters
- Aliases of built-in types
- An overview of c# collections
- Anonymous types
- Arrays
- ASP.NET Identity
- AssemblyInfo.cs Examples
- Async/await, Backgroundworker, Task and Thread Examples
- Async-Await
- Asynchronous Socket
- Attributes
- BackgroundWorker
- BigInteger
- Binary Serialization
-
BindingList
- Built-in Types
- C# 3.0 Features
- C# 4.0 Features
- C# 5.0 Features
- C# 6.0 Features
- C# 7.0 Features
- C# Authentication handler
- C# Script
- Caching
- Casting
- Checked and Unchecked
- CLSCompliantAttribute
- Code Contracts
- Code Contracts and Assertions
- Collection Initializers
- Comments and regions
- Common String Operations
- Conditional Statements
- Constructors and Finalizers
- Creating a Console Application using a Plain-Text Editor and the C# Compiler (csc.exe)
- Creating Own MessageBox in Windows Form Application
- Creational Design Patterns
- Cryptography (System.Security.Cryptography)
- Data Annotation
- DateTime Methods
- Delegates
- Dependency Injection
- Diagnostics
- Dynamic type
- Enum
- Equality Operator
- Equals and GetHashCode
- Events
- Exception Handling
- Expression Trees
- Extension Methods
- File and Stream I/O
- FileSystemWatcher
- Func delegates
- Function with multiple return values
- Functional Programming
- Garbage Collector in .Net
- Generating Random Numbers in C#
- Generic Lambda Query Builder
- Generics
- Getting Started: Json with C#
- Guid
- Handling FormatException when converting string to other types
- Hash Functions
- How to use C# Structs to create a Union type (Similar to C Unions)
- ICloneable
- IComparable
- IDisposable interface
- IEnumerable
- ILGenerator
- Immutability
- Implementing Decorator Design Pattern
- Implementing Flyweight Design Pattern
- Import Google Contacts
- Including Font Resources
- Indexer
- Inheritance
- Initializing Properties
- INotifyPropertyChanged interface
- Interfaces
- Interoperability
- IQueryable interface
- Iterators
- Keywords
- Lambda expressions
- Lambda Expressions
- LINQ Queries
- Aggregate
- All
- Any
- Any and First(OrDefault) - best practice
- Basics
-
Build your own Linq operators for IEnumerable
- Chaining methods
- Concat
- Contains
- Count and LongCount
- DefaultIfEmpty
- Defining a variable inside a Linq query (let keyword)
- Distinct
- ElementAt and ElementAtOrDefault
- Enumerating the Enumerable
- Except
- First, FirstOrDefault, Last, LastOrDefault, Single, and SingleOrDefault
- GroupBy
- GroupBy one or multiple fields
- GroupBy Sum and Count
- GroupJoin with outer range variable
- Incrementally building a query
- Joining multiple sequences
- Joining on multiple keys
- JOINS
- Linq Quantifiers
- OrderBy
- OrderByDescending
- Query collection by type / cast elements to type
- Query Ordering - OrderBy() ThenBy() OrderByDescending() ThenByDescending()
- Range and Repeat
- Reverse
- Select - Transforming elements
-
Select with Func
- SelectMany
- SelectMany: Flattening a sequence of sequences
- SequenceEqual
- Skip and Take
- SkipWhile
- Sum
- TakeWhile
- ToDictionary
- ToLookup
- Union
- Using Range with various Linq methods
- Using SelectMany instead of nested loops
- Where
- Zip
- Linq to Objects
- LINQ to XML
- Literals
- Lock Statement
- Looping
- Making a variable thread safe
- Methods
- Microsoft.Exchange.WebServices
- Named and Optional Arguments
- Named Arguments
- nameof Operator
- Naming Conventions
- Networking
- Nullable types
- Null-Coalescing Operator
- Null-conditional Operators
- NullReferenceException
- O(n) Algorithm for circular rotation of an array
- Object initializers
- Object Oriented Programming In C#
-
ObservableCollection
- Operators
- Overflow
- Overload Resolution
- Parallel LINQ (PLINQ)
- Partial class and methods
- Performing HTTP requests
- Pointers
- Pointers & Unsafe Code
- Polymorphism
- Preprocessor directives
- Properties
- Reactive Extensions (Rx)
- Read & Understand Stacktraces
- Reading and writing .zip files
- Recursion
- Reflection
- Regex Parsing
- Runtime Compile
- Singleton Implementation
- Static Classes
- Stopwatches
- Stream
- String Concatenate
- String Escape Sequences
- String Interpolation
- String Manipulation
- String.Format
- StringBuilder
- Structs
- Structural Design Patterns
- Synchronization Context in Async-Await
- System.DirectoryServices.Protocols.LdapConnection
- System.Management.Automation
- T4 Code Generation
- Task Parallel Library
- Task Parallel Library (TPL) Dataflow Constructs
- Threading
- Timers
- Tuples
- Type Conversion
- Unsafe Code in .NET
- Using Directive
- Using json.net
- Using SQLite in C#
- Using Statement
- Value type vs Reference type
- Verbatim Strings
- Windows Communication Foundation
- XDocument and the System.Xml.Linq namespace
- XML Documentation Comments
- XmlDocument and the System.Xml namespace
- Yield Keyword
C# Language LINQ Queries Count and LongCount
Example
Count returns the number of elements in an IEnumerable<T>. Count also exposes an optional predicate parameter that allows you to filter the elements you want to count.
int[] array = { 1, 2, 3, 4, 2, 5, 3, 1, 2 };
int n = array.Count(); // returns the number of elements in the array
int x = array.Count(i => i > 2); // returns the number of elements in the array greater than 2
LongCount works the same way as Count but has a return type of long and is used for counting IEnumerable<T> sequences that are longer than int.MaxValue
int[] array = GetLargeArray();
long n = array.LongCount(); // returns the number of elements in the array
long x = array.LongCount(i => i > 100); // returns the number of elements in the array greater than 100
