How to return multiple value from method in c#

The actual return value of a C# method can only ever be a single object instance - a class, or a list, or a double for example - but there are ways to get more values back to the calling method.

First you can encapsulate the values you want in a custom class, which holds just the custom class list value and a decimal.

public class ReturnValue
   {
   public List<MyClass> List;
   public double Value;
   }

public ReturnValue MyMethod()
   {
   ReturnValue ret = new ReturnValue();
   ...
   return ret;
   }

That's a little clumsy, but it works.

Then you can use ref and out parameters on your method:

public bool MyMethod(ref List<MyClass> list, out double d)
   {
   foreach(MyClass in list)
      {
      ...
      }
   list = new List<MyClass>();
   ...
   d = 1.23;
   return true;
   }

This can be a lot more flexible, but looks a little rough and ready sometimes.

You can return
1) An object of a class that contains two attributes ( listvalue and decimal).
2) You can return a KeyValuePair[^].
3) Return a Tuple[^] with multiple values.