C# Language
- Getting started with C# Language
- Learn Tutorial
- How to Start Learning C# While Still in College
- Awesome Book
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- .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
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- Attributes
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- BigInteger
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BindingList
- Built-in Types
- C# 3.0 Features
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- C# 7.0 Features
- C# Authentication handler
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- CLSCompliantAttribute
- Code Contracts
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- Collection Initializers
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- 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
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- Functional Programming
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- 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
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- IEnumerable
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- IQueryable interface
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- 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
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- Query collection by type / cast elements to type
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- Range and Repeat
- Reverse
- Select - Transforming elements
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Select with Func
- SelectMany
- SelectMany: Flattening a sequence of sequences
- SequenceEqual
- Skip and Take
- SkipWhile
- Sum
- TakeWhile
- ToDictionary
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- Union
- Using Range with various Linq methods
- Using SelectMany instead of nested loops
- Where
- Zip
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- Microsoft.Exchange.WebServices
- Named and Optional Arguments
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- Networking
- Nullable types
- Null-Coalescing Operator
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- NullReferenceException
- O(n) Algorithm for circular rotation of an array
- Object initializers
- Object Oriented Programming In C#
-
ObservableCollection
- Operators
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- Structs
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- 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
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- 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 ElementAt and ElementAtOrDefault
Example
ElementAt will return the item at index n. If n is not within the range of the enumerable, throws an ArgumentOutOfRangeException.
int[] numbers = { 1, 2, 3, 4, 5 };
numbers.ElementAt(2); // 3
numbers.ElementAt(10); // throws ArgumentOutOfRangeException
ElementAtOrDefault will return the item at index n. If n is not within the range of the enumerable, returns a default(T).
int[] numbers = { 1, 2, 3, 4, 5 };
numbers.ElementAtOrDefault(2); // 3
numbers.ElementAtOrDefault(10); // 0 = default(int)
Both ElementAt and ElementAtOrDefault are optimized for when the source is an IList<T> and normal indexing will be used in those cases.
Note that for ElementAt, if the provided index is greater than the size of the IList<T>, the list should (but is technically not guaranteed to) throw an ArgumentOutOfRangeException.
