{"id":340,"date":"2022-01-05T08:01:00","date_gmt":"2022-01-05T01:01:00","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=340"},"modified":"2022-06-03T13:41:01","modified_gmt":"2022-06-03T06:41:01","slug":"csharp-object-initializer","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-tutorial\/csharp-object-initializer\/","title":{"rendered":"C# Object Initializer"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn about the C# object initializer to assign values to any accessible fields or properties of the object.<\/p>\n\n\n\n

Introduction to the C# object initializer<\/h2>\n\n\n\n

An object initializer allows you to initialize accessible fields and properties<\/a> of an object of a class<\/a>. <\/p>\n\n\n\n

First, define the Person<\/code> class with three public<\/a> properties and two constructors<\/a>:<\/p>\n\n\n

\/\/ Person.cs<\/span>\nclass<\/span> Person<\/span>\n{\n    public<\/span> string<\/span> FirstName { get<\/span>; set<\/span>; }\n    public<\/span> string<\/span> LastName { get<\/span>; set<\/span>; }\n    public<\/span> byte<\/span> Age { get<\/span>; set<\/span>; }\n\n    public<\/span> Person<\/span>(<\/span>)<\/span> \n    {\n    }\n\n    public<\/span> Person<\/span>(string<\/span> firstName, string<\/span> lastName<\/span>)<\/span>\n    {\n        FirstName = firstName;\n        LastName = lastName;\n    }\n}<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Second, create a new instance of the Person<\/code> class and assign values to the Firstname<\/code>, LastName<\/code>, and Age<\/code> properties:<\/p>\n\n\n
\/\/ Program.cs<\/span>\n\nvar<\/span> p1 = new<\/span> Person();\np1.FirstName = \"John\"<\/span>;\np1.LastName = \"Doe\"<\/span>;\np1.Age = 25<\/span>;<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
And use the second constructor to create and initialize another Person<\/code> object:<\/p>\n\n\n
\/\/ Program.cs<\/span>\n\nvar<\/span> p1 = new<\/span> Person();\np1.FirstName = \"John\"<\/span>;\np1.LastName = \"Doe\"<\/span>;\np1.Age = 25<\/span>;\n\n\nvar<\/span> p2 = new<\/span> Person(\"Jane\"<\/span>, \"Doe\"<\/span>);\np2.Age = 22<\/span>;<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Instead of doing it, you can use an object initializer to create a new instance of the Person<\/code> class and assign the values to the object’s properties:<\/p>\n\n\n
var<\/span> p1 = new<\/span> Person\n{\n    FirstName = \"John\"<\/span>,\n    LastName = \"Doe\"<\/span>,\n    Age = 1<\/span>\n};<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Also, you can combine a constructor with an object initializer. The following example calls the second constructor and assigns a value to the Age<\/code> property:<\/p>\n\n\n
var<\/span> p1 = new<\/span> Person(\"John\"<\/span>, \"Doe\"<\/span>) { Age = 1<\/span> };<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Using object initializers with indexers<\/h2>\n\n\n\n
C# allows you to use an object initializer to set an indexer<\/a> in an object. Consider the following example:<\/p>\n\n\n\n
First, defines the Matrix<\/code> class that uses an indexer to get and set elements at a specified row and column:<\/p>\n\n\n
\/\/ Matrix.cs<\/span>\nclass<\/span> Matrix<\/span>\n{\n    private<\/span> double<\/span>[,] data;\n    public<\/span> Matrix<\/span>(int<\/span> row, int<\/span> column<\/span>)<\/span>\n    {\n        data = new<\/span> double<\/span>[row, column];\n    }\n\n    public<\/span> double<\/span> this<\/span>[int<\/span> row, int<\/span> column]\n    {\n        get<\/span> => data[row, column];\n        set<\/span> => data[row, column] = value<\/span>;\n    }\n}<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Second, create a new instance of the Matrix<\/code> class and use an object initializer to assign elements:<\/p>\n\n\n
\/\/ Program.cs<\/span>\nvar<\/span> matrix = new<\/span> Matrix(3<\/span>, 3<\/span>)\n{\n    [0, 0<\/span>] = 1<\/span>,\n    [0, 1<\/span>] = 2<\/span>,\n    [0, 2<\/span>] = 3<\/span>,\n    [1, 0<\/span>] = 4<\/span>,\n    [1, 1<\/span>] = 5<\/span>,\n    [1, 2<\/span>] = 6<\/span>,\n    [2, 0<\/span>] = 7<\/span>,\n    [2, 1<\/span>] = 8<\/span>,\n    [2, 2<\/span>] = 9<\/span>\n};\n\nfor<\/span> (int<\/span> row = 0<\/span>; row < 3<\/span>; row++)\n{\n    for<\/span> (int<\/span> column = 0<\/span>; column < 3<\/span>; column++)\n    {\n        Console.Write($\"{matrix[row, column]}<\/span> \"<\/span>);\n    }\n    Console.WriteLine();\n}<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
1<\/span> 2<\/span> 3<\/span>\n4<\/span> 5<\/span> 6<\/span>\n7<\/span> 8<\/span> 9<\/span><\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Summary<\/h2>\n\n\n\n
  • An object initializer to initialize accessible fields and properties of an object.<\/li><\/ul>\n
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