How can I make a C# class instantiate another class in its constructor?

Question

I created the following: ``` public class HttpStatusErrors { public HttpStatusErrors() { this.Details = new List(); } public string Header { set; get; } public IList Details { set; get; } } public class HttpStatusErrorDetails { public HttpStatusErrorDetails() { this.Errors = new List(); } public string Error { set; get; } public IList Errors { set; get; } } ``` In my code I am using it like this: ``` var msg = new HttpStatusErrors(); msg.Header = "Validation Error"; foreach (var eve in ex.EntityValidationErrors) { msg.Details. // Valid so far msg.Details.Error // Gives the error below: ``` The Ide recognizes msg.Details as being valid but when I try to write the second line I get: ``` Error 3 'System.Collections.Generic.IList' does not contain a definition for 'Error' and no extension method 'Error' accepting a first argument of type 'System.Collections.Generic.IList

Accepted Answer

`msg.Details` returns a `List` object. `List<T>` does not have an `Errors` property. You need to access a specific element in your list, and only then will you have your `Errors` property.

For example:

```
msg.Details[0].Error
```

In your code you might want to make sure that `msg.Details` contains elements before trying to access them, or better yet iterate over them in a `foreach` loop.

How can I make a C# class instantiate another class in its constructor?

Solution

Problem