CODEWITHSUNDEEP
c#objectcollectionsproperties
akinuri
akinuri

Reputation: 12027

JS object like collection in C#

After practicing with JS for some time I've moved to C#. I'm trying to create an object with some properties in C#. In JS I could do it like this:

var person = {
    fname : "",
    lname : "",
    id    : ""
}

I want to create something similar to this in C#. I've watched some tuts and I'm a little confused. There are classes, dictionaries, hashtables. I don't know where to start.

If there is a way to do it without using a constructor I'd prefer to use it. Cus I won't be changing the values and using a constructer is a pain. Object will have like 10+ property so typing them in a single line with the correct order... uh, no.

Upvotes: 1

Views: 1508

Answers (4)

Alex
Alex

Reputation: 13234

In addition to the answers already provided, c# allows both anonymous types and it supports dynamic types. So taking the example you gave, in c# you can do:

Anonymous type:

var person = new {
    fname = "first",
    lname = "last",
    id    = "123"
};
Console.WriteLine(person.lname);

Dynamic type:

    dynamic anotherPerson = new System.Dynamic.ExpandoObject();

    anotherPerson.FirstName = person.lname;
    Console.WriteLine(anotherPerson.FirstName);

    anotherPerson.PrintPerson = (Action<dynamic>)((p => Console.WriteLine("[{0}] {1}. {2}", p.id, p.lname, p.fname)));
    anotherPerson.PrintPerson(person);

These examples are a little contrived. There are specific circumstances where they come in very handy. However unless you really need it, it is preferred to create strongly typed classes. They provide you with a public interface contract that can be verified by the compiler. Also in most scenarios the runtime cost for dynamic types will be substantially higher.

Upvotes: 2

Alessandro D&#39;Andria
Alessandro D&#39;Andria

Reputation: 8878

In c# (4.0 and above) you can use named and optional parameters (http://msdn.microsoft.com/en-us/library/dd264739.aspx), so you can keep your class immutable.

Upvotes: 1

Karl Anderson
Karl Anderson

Reputation: 34844

You can create a C# class with properties, so you can set the properties on separate lines similar to the expando properties syntax of JavaScript, like this:

public class Person
{
    public string fname { get; set; }
    public string lname { get; set; }
    public int id { get; set; }
}

Now you can invoke the class and set the properties, like this:

var person = new Person();
person.fname = "John";
person.lname = "Jones";
person.id = 7;

Also, you can use the object initializer syntax, like this:

var person = new Person {
    fname = "John",
    lname = "Jones",
    id = 7
};

Note: C# is strongly typed so you cannot change the type of a value in a property like you can in JavaScript.

Upvotes: 0

mechenbier
mechenbier

Reputation: 3067

You could create a class "Person"

public class Person {
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int ID { get; set; }
}

And then instantiate a new Person like so:

var p = new Person {
    FirstName = "",
    LastName = "",
    ID = 1
};

And do what you need with that Person

Upvotes: 0

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