public void DivisionTest()
 {
     DivideIt testDiv = new DivideIt();
     ArrayList myNums = new ArrayList();
     myNums.Add(5);
     myNums.Add(5);
     int answer = testDiv.Division(myNums);
     Assert.AreEqual(answer, 1);
 }
        public string Calculate(string input)
        {
            // creates a new RegexProcessor
            RegexUtil regexProcessing = new RegexUtil();

            // creates a new setting ConstantParser
            ConstantParser constantSetting = new ConstantParser();

            // extract integers
            ArrayList integers = regexProcessing.ExtractNums(input);

            // extracts operand
            string thisOp = regexProcessing.ExtractsOp(input);

            // holds answer value
            string answer;

            // make a new instance of the applicable class per the
            // operand extracted
            switch (thisOp)
            {
                case "+":
                    AddIt thisAddExp = new AddIt();
                    answer = thisAddExp.Addition(integers).ToString();
                    LastQnA.LastAns = Convert.ToInt32(answer);
                    LastQnA.LastQ = input;
                    return answer;
                case "-":
                    SubtractIt thisSubExp = new SubtractIt();
                    answer = thisSubExp.Subtraction(integers).ToString();
                    LastQnA.LastAns = Convert.ToInt32(answer);
                    LastQnA.LastQ = input;
                    return answer;
                case "*":
                    MultiplyIt thisMultiExp = new MultiplyIt();
                    answer = thisMultiExp.Multiplication(integers).ToString();
                    LastQnA.LastAns = Convert.ToInt32(answer);
                    LastQnA.LastQ = input;
                    return answer;
                case "/":
                    DivideIt thisDivExp = new DivideIt();
                    answer = thisDivExp.Division(integers).ToString();
                    LastQnA.LastAns = Convert.ToInt32(answer);
                    LastQnA.LastQ = input;
                    return answer;
                case "%":
                    ModIt thisModExp = new ModIt();
                    answer = thisModExp.Modulation(integers).ToString();
                    LastQnA.LastAns = Convert.ToInt32(answer);
                    LastQnA.LastQ = input;
                    return answer;
                case "=":
                    answer = "Your value has been set";
                    return answer;
                default: throw new ArgumentException("Input doesn't contain an operand understood {0}", thisOp);
            }
        }
        // this is going to extract which type of expression it is
        public string ExtractsOp(string input)
        {
            Match AddMatch = add_regex.Match(input);
            Match DivideMatch = divide_regex.Match(input);
            Match MultiMatch = multiply_regex.Match(input);
            Match SubMatch = subt_regex.Match(input);
            Match ModMatch = mod_regex.Match(input);

            if (AddMatch.Success)
            {
                AddIt thisAdd = new AddIt();
                return "+";
            }
            else if (SubMatch.Success)
            {
                SubtractIt thisSub = new SubtractIt();
                return "-";
            }
            else if (MultiMatch.Success)
            {
                MultiplyIt thisMult = new MultiplyIt();
                return "*";
            }
            else if (DivideMatch.Success)
            {
                DivideIt thisDiv = new DivideIt();
                return "/";
            }
            else if (ModMatch.Success)
            {
                ModIt thisMod = new ModIt();
                return "%";
            }
            else
            {
               throw new ArgumentException("No operator provided");
            }
        }