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1. Top results related to how to initialize a dictionary in c# class

   • How to initialize a derived class in C#?

     Top Answer

     Answered Jun 25, 2009 · 20 votes

     You want to use this syntax to call the base constructor:

     public class RegistarAnuncio : Processor{ public RegistarAnuncio(ParsedString parsedMessage, Utilizador utilizador) : base (parsedMessage, utilizador) { }}

     I have an article on constructors which goes into more detail. Very briefly:

     • You can use base(arguments) or this(arguments) - the first version calls a base class constructor, the second calls another constructor in the same class
     • If you don't specify anything, it's like having base()
     • You can't make the constructor calls circular (i.e. one constructor calling another which calls the first)
     • You can only chain to one constructor (but that one may chain to another)
     • The constructor call occurs immediately before the constructor body is executed, but after any instance variable initializers

     One common use for "this" is to use default values. For instance:

     const string DefaultFirstValue = "fred";const int DefaultSecondValue = 20;-public Foo(string firstValue, int secondValue){ this.firstValue = firstValue; this.secondValue = secondValue;}public Foo(string firstValue) : this(firstValue, DefaultSecondValue){}public Foo(int secondValue) : this(DefaultFirstValue, secondValue){}public Foo() : this(DefaultFirstValue, DefaultSecondValue){}

     With C# 4, this will be less useful as there will be optional parameters and named arguments. You may still wish to provide the overloads for languages which don't support those features, of course.

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     1/5

   • How to initialize a two dimension array for a Matrix class in C#

     Top Answer

     Answered Nov 03, 2021 · 1 votes

     You actually have a jagged array, i.e. array of array: int[][], note that 2d array is int[,]

     To initialize int[][] you have to create each inner array:

     public Matrix(int m, int n) { array = new int[m][]; // outer array of size m which- for (int i = 0; i < n; ++i) // contains array[i] = new int[n]; // arrays of length n }

     You can use Linq for shorter syntax:

     using System.Linq;- ... public Matrix(int m, int n) { array = Enumerable .Range(0, m) .Select(_ => new int[n]) .ToArray(); }

     Edit: Possible Matrix implementation:

     class Matrix { private int[][] array;- public Matrix(int rows, int columns) { if (rows <= 0) throw new ArgumentOutOfRangeException(nameof(rows)); if (columns <= 0) throw new ArgumentOutOfRangeException(nameof(columns)); array = Enumerable .Range(0, rows) .Select(_ => new int[columns]) .ToArray(); } public int RowCount => array.Length; public int ColumnCount => array[0].Length; public int this[int row, int column] { get { if (row < 0 || row >= array.Length) throw new ArgumentOutOfRangeException(nameof(row)); if (column < 0 || column >= array[row].Length) throw new ArgumentOutOfRangeException(nameof(column)); return array[row][column]; } set { if (row < 0 || row >= array.Length) throw new ArgumentOutOfRangeException(nameof(row)); if (column < 0 || column >= array[row].Length) throw new ArgumentOutOfRangeException(nameof(column)); array[row][column] = value; } } }

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     2/5

   • How to create a class from a Dictionary in C#?

     Top Answer

     Answered Jun 17, 2019 · 5 votes

     Your requirements are not clearly stated, but I'm guessing you are looking for a dymamic type that has properties whose names map to dictionary keys.

     In that case you can use a simple dictionary wrapper like this one:

     class DynamicDictionaryWrapper : DynamicObject{ protected readonly Dictionary<string,object> _source; public DynamicDictionaryWrapper(Dictionary<string,object> source) { _source = source; } public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; return (_source.TryGetValue(binder.Name, out result)); }}

     Which you can use this way:

     public static void Main(){ var myDictionary = new Dictionary<string, dynamic> { { "ID1", 12 }, { "ID2", "Text2"}, { "ID3", "Text3" } }; dynamic myObject = new DynamicDictionaryWrapper(myDictionary); Console.WriteLine(myObject.ID1); Console.WriteLine(myObject.ID2); Console.WriteLine(myObject.ID3);}

     Output:

     12Text2Text3

     Link to working example on DotNetFiddle

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     3/5

   • How to modify key in a dictionary in C#

     Top Answer

     Answered Mar 19, 2013 · 51 votes

     As Jason said, you can't change the key of an existing dictionary entry. You'll have to remove/add using a new key like so:

     // we need to cache the keys to update since we can't// modify the collection during enumerationvar keysToUpdate = new List<int>();-foreach (var entry in dict){ if (entry.Key < MinKeyValue) { keysToUpdate.Add(entry.Key); }}foreach (int keyToUpdate in keysToUpdate){ SortedDictionary<string, List<string>> value = dict[keyToUpdate]; int newKey = keyToUpdate + 1; // increment the key until arriving at one that doesn't already exist while (dict.ContainsKey(newKey)) { newKey++; } dict.Remove(keyToUpdate); dict.Add(newKey, value);}

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     4/5

   • How to initialize a BigInteger in C#?

     Top Answer

     Answered Apr 13, 2010 · 9 votes

     It should be there, did you remember to add a reference?

     Right click your project, click Add Reference, then in the leftmost tab, select System.Numerics

     Then you can add it and use it.

     Other Answers

     Answered Sep 25, 2017 · 3 votes

     You need to add the reference System.Numerics yourself as mentioned in other answers, the System.Numerics.dll should be there if you have .NET 4 installed.

     Then, if your value is really a big one and you try:

     var myBigInteger = new BigInteger(50000000000000000000000000000000000000000000);-

     You will get a compilation error:

     Bad compile constant value

     The simplest approach is to use a text literal:

     var myBigInteger = BigInteger.Parse("50000000000000000000000000000000000000000000");-

     Other Answers

     Answered Apr 13, 2010 · 2 votes

     What version of .NET 4 is your project targeting? Make sure it is targeting the entire framework not the client profile. I have just confirmed that System.Numerics.dll is part of .NET 4 Client Profile so this shouldn't be the problem.

     Once you have done this make sure that you have referenced System.Numerics.dll in your project as well.

     Check all answers on Stack Overflow

     5/5

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2. stackoverflow.com › questions › 17047602Proper way to initialize a C# dictionary with values

   stackoverflow.com › questions › 17047602

   • Cached

   With C# 6.0, you can create a dictionary in the following way: var dict = new Dictionary<string, int> { ["one"] = 1, ["two"] = 2, ["three"] = 3 }; It even works with custom types.

   Code sample

   var myDict = new Dictionary<string, string> {

     { "key1", "value1" },

     { "key2", "value2" }

   };

   Console.ReadKey();...

   See more on stackoverflow

3. learn.microsoft.com › en-us › dotnetHow to initialize a dictionary with a collection initializer ...

   learn.microsoft.com › en-us › dotnet

   • Cached

   • Overview
   • Example
   • See also

   A Dictionary contains a collection of key/value pairs. Its Add method takes two parameters, one for the key and one for the value. One way to initialize a Dictionary , or any collection whose Add method takes multiple parameters, is to enclose each set of parameters in braces as shown in the following example. Another optio...

   See full list on learn.microsoft.com

   In the following code example, a Dictionary is initialized with instances of type StudentName. The first initialization uses the Add method with two arguments. The compiler generates a call to Add for each of the pairs of int keys and StudentName values. The second uses a public read / write indexer method of the Dictionary class:

   Note the two pairs of braces in each element of the collection in the first declaration. The innermost braces enclose the object initializer for the StudentName, and the outermost braces enclose the initializer for the key/value pair that will be added to the students Dictionary . Finally, the whole collection initializer for the dictionary is enclosed in braces. In the second initialization, the left side of the assignment is the key and the right side is the value, using an object initializer for StudentName.

   See full list on learn.microsoft.com

   •C# Programming Guide

   •Object and Collection Initializers

   See full list on learn.microsoft.com

4. stackoverflow.com › questions › 313324c# - Declare a dictionary inside a static class - Stack Overflow

   stackoverflow.com › questions › 313324

   • Cached

   Nov 24, 2008 · You can use the static/class constructor to initialize your dictionary: public static class ErrorCode { public const IDictionary<string, string> ErrorCodeDic; public static ErrorCode() { ErrorCodeDic = new Dictionary<string, string>() { {"1", "User name or password problem"} }; } }

5. www.techiedelight.com › initialize-dictionary-csharpInitialize a Dictionary in C# | Techie Delight

   www.techiedelight.com › initialize-dictionary-csharp

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   Apr 6, 2024 · 1. Collection Initializer. To initialize a dictionary, we can enclose each set of key-value in curly braces. Internally for each pair, the compiler makes a call to Dictionary’s Add () method. This is demonstrated below: Download Run Code. 2. Index Initializer. We can also initialize a dictionary using an index initializer, as shown below.

6. www.delftstack.com › howto › csharpHow to Initialize a Dictionary in C# | Delft Stack

   www.delftstack.com › howto › csharp

   • Cached

   Feb 2, 2024 · The Dictionary<key, value> class can be used to create a dictionary in C#. We can use the constructor of the Dictionary<key, value> class to initialize a dictionary in C#. The following code example shows us how we can initialize a dictionary with the constructor of the Dictionary<key, value> class in C#.

7. People also ask

   How to initialize a dictionary in C#?

   • This post will discuss how to initialize a dictionary in C#. 1. Collection Initializer To initialize a dictionary, we can enclose each set of key-value in curly braces. Internally for each pair, the compiler makes a call to Dictionary’s Add() method. This is demonstrated below: 2. Index Initializer

   Initialize a Dictionary in C# | Techie Delight

   www.techiedelight.com/initialize-dictionary-csharp/

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   How to initialize a dictionary of class objects with the new operator?

   • The following code example shows us how we can initialize a dictionary of class objects with the new operator in C#. public class Person { private string name; private string email; public Person(string n, string e) { name = n; email = e; } class Program { static void Main(stringargs) {

   How to Initialize a Dictionary in C# | Delft Stack

   www.delftstack.com/howto/csharp/initialize-dictionary-in-csharp/

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   How to create a dictionary in C#?

   • Dictionary Builder To create a dictionary with several entries, it’s better to create a type-safe DictionaryBuilder class. Then we can use Builder’s Add() method, which takes key-value pairs instead of a dictionary. The Add() associates key with value in the built dictionary. That’s all about initializing a Dictionary in C#.

   Initialize a Dictionary in C# | Techie Delight

   www.techiedelight.com/initialize-dictionary-csharp/

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   Why is it called a dictionary in C#?

   • It's called a Dictionary because the key is used to look up the corresponding value, just like in a real dictionary. The good thing is that the dictionary is a generic, so we can use it to store values of any type. To initialize a dictionary in C#, we first need to provide the type for the key and the type for the value.

   C# Dictionary: Complete Guide [2023] - Josip Miskovic

   josipmisko.com/posts/c-sharp-dictionary

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8. josipmisko.com › posts › c-sharp-dictionaryC# Dictionary: Complete Guide [2023] – Josip Miskovic

   josipmisko.com › posts › c-sharp-dictionary

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   Jan 26, 2023 · To initialize a dictionary in C#, we first need to provide the type for the key and the type for the value. For example, for a dictionary that stores the name and age of a person, the initialization would be: C# Dictionary<string, int> nameToAge = new Dictionary<string, int>(); The first type inside the angle brackets is the key type.

9. makolyte.com › csharp-initialize-a-dictionaryC# - Initialize a dictionary | MAKOLYTE

   makolyte.com › csharp-initialize-a-dictionary

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   Sep 12, 2023 · You can declare a dictionary and initialize it with values by using the collection initializer syntax. Within the initializer block, you have two options for adding key/value pairs to the dictionary: Indexer syntax, like [key] = value. Curly brace syntax, like { key, value }. I’ll show examples of both options below.