collection-initializer

When I run this code , it doesn't initialize ThisIsAList to an empty collection as I was expecting... instead ThisIsAList was null. void Main() { var thing = new Thing { ThisIsAList = {} }; Console.WriteLine(thing.ThisIsAList == null); // prints "True" } public class Thing { public List<string> ThisIsAList { get; set; } } Why isn't this a compile error? Why is the result null ? I was wondering if maybe there was an implicit conversion going on here, but the following attempts produced compile errors: thing.ThisIsAList = Enumerable.Empty<string>().ToArray(); List<int> integers = { 0, 1, 2, 3 };

I've read that : The team have generally been busy implementing other variations on initializers. For example you can now initialize a Dictionary object But looking at : var Dic = new Dictionary<string,int>{ {"x",3}, {"y",7} }; VS var Dic = new Dictionary<string,int>{ ["x"]=3, ["y"]=7 }; I don't see where the benefit is. it looks the same. Both are nothing more than a name-value collection. They swapped pairs of curly braces for pairs of square brackets and some commas Question: What is the added value for using the new syntax ? a real world example would be much appreciated. The main

Is is possible to combine a List initializer and object initializer at the same time? Given the following class definition: class MyList : List<int> { public string Text { get; set; } } // we can do this var obj1 = new MyList() { Text="Hello" }; // we can also do that var obj2 = new MyList() { 1, 2, 3 }; // but this one doesn't compile //var obj3 = new MyList() { Text="Hello", 1, 2, 3 }; Is this by design or is it just a bug or missing feature of the c# compiler? No, looking at the definitions from section 7.6.10 of the C# spec, an object-or-collection-initializer expression is either an