What does Model.(Variable) do?

Question

Okay, so I've got this code:

    public ActionResult Welcome(string name = "", int numTimes = 1)
    {
        var viewModel = new WelcomeViewModel
        {
            Message = "Hello " + name,
            NumTimes = numTimes
        };

        return View(viewModel);
    }
    public class WelcomeViewModel
    {
        public string Message { get; set; }
        public int NumTimes { get; set; }
    }

and the view in Welcome() is:

<h2>Welcome</h2>

<% for(int i = 0; i < Model.NumTimes; i++) {%>

    <h3><%: Model.Message; %></h3>
<%} %>

Firstly, when I run this, I get an error when running .../Welcome?name=Scott&numtimes=4 saying that in the line

<h3><%: Model.Message; %></h3>

it expects ')'

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. Compiler Error Message: CS1026: ) expected

why is this?

---

Secondly what is this whole Model thing? What does it do?

Answer 1

It's because the <%: Model.Message; %> translates (basically) into:

Response.Write(Model.Message;);

As you see, the semicolon should not be there. The compiler expects the ending parentheses before there is a semicolon, hence the error message.

The "Model thing" is the M in MVC. The Model is the data that the View displays. Each view has a single Model, so the Model contains all the data that the View needs.