Three ways to implement Eval (string expression) in C#

    public class Class1
    {
        #region Method 1: Use CodeCom        [Obsolete]
         comp = new ().CreateCompiler();
         cp = new ();
        public object Eval_1(string Expression)
        {
            StringBuilder code = new StringBuilder();
            ("using System; \n");
            ("namespace ADOGuy { \n");
            (" public class _Evaluator { \n");
            (" public object __foo() ");
            ("{ ");
            (" return ({0}); ", Expression);
            ("}\n");
            ("} }");
             cr = (cp, ());
             a = ;
            object _Compiled = ("ADOGuy._Evaluator");
             mi = _Compiled.GetType().GetMethod("__foo");
            return (_Compiled, null);
        }
        #endregion

        #region Method 2: Analysis of expressions        string Precede(string p, string q)
        {
            switch (p)
            {
                case "+":
                case "-":
                    return ("*/(".IndexOf(q) != -1) ? "<" : ">";
                case "*":
                case "/":
                    return (q == "(") ? "<" : ">";
                case "(":
                    return (q == ")") ? "=" : "<";
                case ")":
                    return (q == "(") ? "?" : ">";
                case "#":
                    return (q == "#") ? "=" : "<";
            }
            return "?";
        }

        Double Operate(Double a, char o, Double b)
        {
            switch (o)
            {
                case '+':
                    return a + b;
                case '-':
                    return a - b;
                case '*':
                    return a * b;
                case '/':
                    return a / b;
            }
            return 0;
        }

        public Object Eval_2(string Expression)
        {
            Stack nArr = new Stack(), oArr = new Stack();
            int j = 0;
            Double a = 0, b = 0;
            string w = "";
            char o;
            MatchCollection arr = ((" ", "") + "#", @"(((?<=(^|\())-)?\d+(\.\d+)?|\D)");
            ('#');
            w = (arr[j++]);
            while (!(w == "#" && (()) == "#"))
            {
                if ("+-*/()#".IndexOf(w) != -1)
                {
                    switch (Precede(().ToString(), w))
                    {
                        case "<":
                            (w);
                            w = (arr[j++]);
                            break;
                        case "=":
                            ();
                            w = (arr[j++]);
                            break;
                        case ">":
                            o = (());
                            b = (());
                            a = (());
                            (Operate(a, o, b));
                            break;
                        default:
                            return "Error";
                    }
                }
                else
                {
                    (w);
                    w = (arr[j++]);
                }
            }
            return ();
        }
        #endregion

        #region Method 3: Eval using JScript        // Requires a quote        [Obsolete]
        readonly  ve = ();

        [Obsolete]
        public object Eval_3(string Expression)
        {
            return (Expression, ve);
        }
        #endregion
    }

        static void Main(string[] args)
        {
            String strExpression = "-12 * ( - 2.2 + 7.7 ) - 44 * 2";

            var obj = new Class1();
            ($"Method 1（CodeComLaw）Calculation results：{obj.Eval_1(strExpression)}");
            ($"方Law二（分析Law）Calculation results：{obj.Eval_2(strExpression)}");
            ($"方Law三（JScriptLaw）Calculation results：{obj.Eval_3(strExpression)}");
            ();
        }