Literal notation for Dictionary in C#?

Question

I currently have a WebSocket between JavaScript and a server programmed in C#. In JavaScript, I can pass data easily using an associative array:

var data = {'test': 'val',
            'test2': 'val2'};

To represent this data object on the server side, I use a Dictionary<string, string>, but this is more 'typing-expensive' than in JavaScript:

Dictionary<string, string> data = new Dictionary<string,string>();
data.Add("test", "val");
data.Add("test2", "val2");

Is there some kind of literal notation for associative arrays / Dictionarys in C#?

Answer 1

You use the collection initializer syntax, but you still need to make a new Dictionary<string, string> object first as the shortcut syntax is translated to a bunch of Add() calls (like your code):

var data = new Dictionary<string, string>
{
    { "test", "val" }, 
    { "test2", "val2" }
};

In C# 6, you now have the option of using a more intuitive syntax with Dictionary as well as any other type that supports indexers. The above statement can be rewritten as:

var data = new Dictionary<string, string>
{
    ["test"] = "val",
    ["test2"] = "val2"
};

Unlike collection initializers, this invokes the indexer setter under the hood, rather than an appropriate Add() method.