Question

I have code like this:

public class test {
    public string aa { get; set; }
    public string bb { get; set; }
    public string cc { get; set; }
}

var a = new test {
    aa = "a",
    bb = "b"
}

var d = a;
d.cc = "c";

Is there any way for me to create class d and at the same time populate it. So for example the last two lines could be combined into one? Note that I want to avoid doing this with a constructor as sometime it will be different fields other than cc which I will populate.

please note my edit

var d = a;

Answer 1

Given your new description of the problem, how about this:

Note that it changes a as well (same as your code), it doesn’t create a copy. If you want a copy, go with Oded’s solution.

public class test
{
    public string aa { get; set; }
    public string bb { get; set; }
    public string cc { get; set; }

    public test AlterTest(Action<test> alteration)
    {
        alteration(this);
        return this;
    }
}

static void Main(string[] args)
{
    var a = new test
    {
        aa = "a",
        bb = "b"
    };

    var d = a.AlterTest((t) => t.cc = "c");
}

I’d say this isn’t as readable as your original code though (as you need to know what AlterTest does, which isn’t a lot).