Does C# support the use of static local variables?

Question

Related: How do I create a static local variable in Java?

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Pardon if this is a duplicate; I was pretty sure this would have been

Answer 1

Nesting the related members in an inner class as you have shown in question is the cleanest most probably. You need not push your parent method into inner class if the static variable can somehow get the caller info.

public class MyClass 
{
    ...
    class Helper
    {
        static Regex re = new Regex("\\(copy (\\d+)\\)$");
        string caller;

        internal Helper([CallerMemberName] string caller = null)
        {
            this.caller = caller;
        }

        internal Regex Re
        {
            //can avoid hard coding
            get
            {
                return caller == "AppendCopyToFileName" ? re : null;
            }
            set
            {
                if (caller == "AppendCopyToFileName")
                    re = value;
            }
        }
    }


    private static string AppendCopyToFileName(string f)
    {
        var re = new Helper().Re; //get
        new Helper().Re = ...; //set
    }


    private static void Foo() 
    {
        var re = new Helper().Re; //gets null
        new Helper().Re = ...; //set makes no difference
    }
}

1. You can avoid hard coding of method names in the property using some expression tree tricks.

2. You can avoid the helper constructor and make the property static, but you need to get the caller info inside the property, via using StackTrace.

Lastly, there is always const possible inside a method, but then one, it's not variable, two, only compile time constants are allowed. Just stating.