How to assign a variable with .ConvertToString() method in C# to parse the message?

Question

I am looking to learn how to assign a name to the newly converted string and then parse that string based on

string[] separatingStrings = { ",", "<<", ">>" };
string[] messages = message.Split(separatingStrings);
Console.WriteLine($"{messages.Length} substrings in text:");

below contains the var message converted to a string.

What is the name of the string so I can parse it and output it into unity debug.log?

private void ReceiveMessageLoop()
{
    while (true)
    {
        var message = new NetMQMessage();
        if (!_socket.TryReceiveMultipartMessage(MessageCheckRate, ref message, 2)) continue;

        _messageSubject.OnNext(message);
        Console.WriteLine($"0:{message[0].ConvertToString()} 1:{message[1].ConvertToString()}");
         //Console.WriteLine(message);       
    }
}

Answer 1

You can't declare a variable in a string interpolation expression.

Console.WriteLine($"{string bar = "hello"}"); // This gives error CS1525: Invalid expression term 'string'

So instead, declare it outside the string interpolation, and you can assign it in the interpolation expression with an assignment expression.

string bar;
Console.WriteLine($"{bar = "hello"}"); // This is OK
Console.WriteLine(bar);

Your specific example:

string msg0, msg1;
Console.WriteLine($"0:{msg0 = message[0].ConvertToString()} 1:{msg1 = message[1].ConvertToString()}");
Console.WriteLine(msg0);
Console.WriteLine(msg1);

Bonus tip: You can, however, use an out variable declaration in an interpolation expression. The scope is the same as the line (not somehow local to the interpolation expression). e.g.:

class Program
{
    static string Test(out string x, string y) {
        return x = y;
    }

    static void Main(string[] args)
    {
        Console.WriteLine($"{Test(out string bar, "Hello")}");
        Console.WriteLine(bar);
    }
}