CODEWITHSUNDEEP
c#dictionary
kd7iwp
kd7iwp

Reputation: 3140

How to insert values into C# Dictionary on instantiation?

Does anyone know if there is a way I can insert values into a C# Dictionary when I create it? I can, but don't want to, do dict.Add(int, "string") for each item if there is something more efficient like: 

Dictionary<int, string>(){(0, "string"),(1,"string2"),(2,"string3")};

Upvotes: 160

Views: 91191

Answers (8)

Henk Holterman
Henk Holterman

Reputation: 273179

You were almost there:

var dict = new Dictionary<int, string>()
{ 
   {0, "string"}, 
   {1, "string2"},
   {2, "string3"}
};

Upvotes: 15

Jacksonkr
Jacksonkr

Reputation: 32207

This isn't generally recommended but in times of uncertain crises you can use

Dictionary<string, object> jsonMock = new Dictionary<string, object>() { { "object a", objA }, { "object b", objB } };

// example of unserializing
ClassForObjectA anotherObjA = null;
if(jsonMock.Contains("object a")) {
    anotherObjA = (ClassForObjA)jsonMock["object a"];
}

Upvotes: -2

russelrillema
russelrillema

Reputation: 462

Just so you know as of C# 6 you can now initialize it as follows

var students = 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}
};

Much cleaner :)

Upvotes: 9

user4410190
user4410190

Reputation:

Hope it will work perfectly.

Dictionary<string, double> D =new Dictionary<string, double>(); D.Add("String", 17.00);

Upvotes: -1

Daniel Earwicker
Daniel Earwicker

Reputation: 116654

There's whole page about how to do that here:

http://msdn.microsoft.com/en-us/library/bb531208.aspx

Example:

In the following code example, a Dictionary<TKey, TValue> is initialized with instances of type StudentName:

var students = 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}}
};

Upvotes: 219

matendie
matendie

Reputation: 763

You can also use Lambda expressions to insert any Key Value pairs from any other IEnumerable object. Key and value can be any type you want.

Dictionary<int, string> newDictionary = 
                 SomeList.ToDictionary(k => k.ID, v => v.Name);

I find that much simpler since you use the IEnumerable objects everywhere in .NET

Hope that helps!!!

Tad.

Upvotes: 11

Joseph
Joseph

Reputation: 25513

You can instantiate a dictionary and add items into it like this:

var dictionary = new Dictionary<int, string>
    {
        {0, "string"},
        {1, "string2"},
        {2, "string3"}
    };

Upvotes: 7

Timothy Carter
Timothy Carter

Reputation: 15785

Dictionary<int, string> dictionary = new Dictionary<int, string> { 
   { 0, "string" }, 
   { 1, "string2" }, 
   { 2, "string3" } };

Upvotes: 50

Related Questions