how to string.join object array parameters with customize output

Question

I have an object like that

    public class MyModel
    {
        public int Key { get; set; }
        public string Value { get; set; } 
    }

And I have model like List<MyModel>

    model[0]=new MyModel(){Key = 1,Value ="Something"};
    model[1]=new MyModel(){Key = 3,Value ="Something else"};

I want this output:

    1. Value is = Something //there is \n here
    3. Value is = Something else

So the seperator is \n and while string.join(" \n ", ? ) what should I do?

Is that possible or not? I did it like that but I want to learn can I string.join() do that:

    var newArray = model.Select(x => ((x.Key)+". Value is ="+x.Value));
    string.join(" \n ",newArray );

Sorry for my bad english...

Answer 1

var modelList = new List<MyModel>(){
        new MyModel(){ Key = 1, Value = "Value 1"},
        new MyModel(){ Key = 3, Value = "Value 2 with Key3"}
    };
    
    var stringArray = modelList.Select(model=> $"{model.Key}. Value={model.Value}");
    var finalString = String.Join('\n', stringArray);
    Console.Write(finalString);

https://dotnetfiddle.net/buCe8P

Answer 2

You did well. There are other ways but they are no more correct (in some cases at least).

Example with custom ToString method:

var all = string.Join("\n", model);

public class MyModel
{
    public int Key { get; set; }
    public string Value { get; set; }

    public override string ToString() => $"{Key}. Value Is: {Value}";
}

Or directly with project array:

var all = string.Concat(model.Select(x => $"{x.Key}. Value Is: {x.Value}\n"));

but there's an unnecessary line brake at the end.