dictionary in c# code example

Example 1: c# initialize dictionary

Dictionary<int, string> dictNew = new Dictionary<int,string>()
{
  {1, "true"},
  {2, "false"}
}

Example 2: c sharp create dictionary

// To initialize a dictionary, see below:
IDictionary<int, string> dict = new Dictionary<int, string>();
// Make sure to give it the right type of key and value

// To add values use 'Add()'
dict.Add(1,"One");
dict.Add(2,"Two");
dict.Add(3,"Three");

// You can also do this together with the creation
IDictionary<int, string> dict = new Dictionary<int, string>()
{
	{1,"One"},
	{2, "Two"},
	{3,"Three"}
};

Example 3: c# dictionary first

dictionary.Keys.First();

Example 4: declare dictionary c#

var students2 = new Dictionary<int, StudentName>()
        {
            [111] = new StudentName { FirstName="Sachin", LastName="Karnik", ID=211 },
            [112] = new StudentName { FirstName="Dina", LastName="Salimzianova", ID=317 } ,
            [113] = new StudentName { FirstName="Andy", LastName="Ruth", ID=198 }
        };

Example 5: c# dictionaries

IDictionary<int, string> dict = new Dictionary<int, string>();
        
//or

Dictionary<int, string> dict = new Dictionary<int, string>();

Example 6: dictionary c#

IDictionary<int, string> numberNames = new Dictionary<int, string>();
numberNames.Add(1,"One"); //adding a key/value using the Add() method
numberNames.Add(2,"Two");
numberNames.Add(3,"Three");

//The following throws run-time exception: key already added.
//numberNames.Add(3, "Three"); 

foreach(KeyValuePair<int, string> kvp in numberNames)
    Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);
		
//creating a dictionary using collection-initializer syntax
var cities = new Dictionary<string, string>(){
	{"UK", "London, Manchester, Birmingham"},
	{"USA", "Chicago, New York, Washington"},
	{"India", "Mumbai, New Delhi, Pune"}
};
		
foreach(var kvp in cities)
    Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);