Missing comparison points

[sylvain-fr]

C# properties are missing:
public class Example
{
private int myInt;
public int ReadOnly {get {return myInt;}}
public int Automatic {get; private set;}}
}
Advanced reflections example are missing. Usage of Expression and LinqToSql is very important and powerfull.
Action<>, Func<>,...
Attributes usages ?
... ?

[AshleighAdams]

Not to mention the lacking of primary constructors:

data class Customer(var id: Long, var name: String)

Can be turned into this C# (and use record struct for a value-type):

record Customer(long Id, string Name);

And for the class example, this Kotlin:

open class NamedShape(val name: String) {
    var numberOfSides = 0

    open fun simpleDescription() =
        "A shape with $numberOfSides sides."
}

class Square(var sideLength: Double, name: String) :
        NamedShape(name) {
    init {
        numberOfSides = 4
    }

    fun area() = sideLength.pow(2)

    override fun simpleDescription() =
        "A square with sides of length $sideLength."
}

val square = Square(5.2, "My square")
val area = square.area()
val desc = square.simpleDescription()

Should be compared to more idiomatic C# code:

class NamedShape(string name)
{
    protected virtual int NumberOfSides { get; }

    public virtual string SimpleDescription =>
         $"A shape with {NumberOfSides} sides.";
}

class Square(double sideLength, string name) : NamedShape(name)
{
    protected override NumberOfSides => 4;

    public double Area => Math.Pow(sideLength, 2);

    public override string SimpleDescription =>
        $"A square with sides of length {sideLength}.";
}

var square = new Square(5.2, "My square");
var area = square.Area;
var desc = square.SimpleDescription;

Something else I find very bad faith is this line:

var customer = new Customer { Id  = 1, Name = "Sachin" };
customer.Id = 2 // Error

This is intentionally an error, if you want to change the id, then you must do it explicitly in an initialization context, something which Kotlin lacks:

customer = customer with { Id = 2 };

PS: required properties also tie in to nullable properties and are worth a mention