Note: This article was originally published in 2011. Some steps, commands, or software versions may have changed. Check the current .Net documentation for the latest information.

Prerequisites

Before you begin, make sure you have:

  • Visual Studio or .NET CLI installed
  • .NET Framework or .NET Core SDK
  • Basic C# programming knowledge

How to: Initialize a Dictionary with a Collection Initializer

Sometimes in your project you want to initialize a Dictionary or other sort of collection at the declaration level so you don’t have to manually use the .add() methods and write a separate method in which to execute them. A prime example is a dictionary that is going to be static and used across the entire application and you don’t expect it to change. The code below offers an example of how to initialize a dictionary when you’re declaring the variable:

Dictionary<int, StudentInfo> students = new Dictionary<int, StudentInfo>()
{
    { 111, new StudentInfo {FirstName="Sachin", LastName="Karnik", PhoneNumber="123-456-7890"}},
    { 112, new StudentInfo {FirstName="Dina", LastName="Salimzianova", PhoneNumber="123-456-7890"}},
    { 113, new StudentInfo {FirstName="Andy", LastName="Ruth", PhoneNumber="123-456-7890"}}
};


StudentInfo