private void PerformOperator(OperatorType oprt)
{
if (_operation.FirstValue == "")
{
if (label1.Text != "")
{
_operation.FirstValue = label1.Text;
_operation.Operator = oprt;
label1.Text = "";
}
return;
}
if (label1.Text != "")
{
_operation.SecondValue = label1.Text;
var result = _operation.Calculate();
if (double.IsInfinity(Convert.ToDouble(result)))
{
label2.Text = "Cannot divide by zero";
}
else
{
_operation.FirstValue = result;
label2.Text = result;
_operation.SecondValue = string.Empty;
label1.Text = string.Empty;
_operation.Operator = oprt;
}
}
else
{
_operation.Operator = oprt;
}
}
public double Calculate()
{
return(oper.Calculate(NumberA, NumberB));
}
protected void OpButton_Click(object sender, EventArgs e)
{
Button Button = (Button)sender;
string ButtonText = Button.Text;
// if last entry is a digit, calculate the new result and record the new operand and add it to the expression
if (char.IsDigit(LastEntry))
{
Operation.SecondNumber = Double.Parse(CurrNumberString);
CurrNumberString = Math.Round(Operation.Calculate(), 10).ToString();
Operation.FirstNumber = Double.Parse(CurrNumberString);
Operation.Operand = ButtonText;
if (Expression == "")
{
Expression = CurrNumberString;
}
Expression = Expression.Insert(Expression.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
}
else if (LastEntry == '=')
{
Expression = CurrNumberString.Insert(CurrNumberString.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
}
// if last entry is not a digit, aka it's an operand, update the operation and change the expression and last entry
else
{
Operation.Operand = ButtonText;
if (Expression != "")
{
Expression = Expression.Remove(Expression.Length - 1);
}
else
{
Expression = CurrNumberString;
}
Expression = Expression.Insert(Expression.Length, ButtonText);
LastEntry = Expression[Expression.Length - 1];
}
ExpressionText.Text = Expression;
CurrNumberText.Text = CurrNumberString;
if (Operation.OperationFlag == 1)
{
CurrNumberText.Text = "Cannot divide by zero";
CurrNumberString = "0";
Expression = "";
ExpressionText.Text = Expression;
LastEntry = '0';
Operation.OperationFlag = 0;
}
else if (Operation.OperationFlag == 2)
{
CurrNumberText.Text = "Result is undefined";
CurrNumberString = "0";
Expression = "";
ExpressionText.Text = Expression;
LastEntry = '0';
Operation.OperationFlag = 0;
}
Session["CurrNumberString"] = CurrNumberString;
Session["Expression"] = Expression;
Session["LastEntry"] = LastEntry;
Session["Operation"] = Operation;
}
private string ParseOperation()
{
string numbers = "0123456789.";
string operators = "+-*/";
try
{
string userInput = this.userInputText.Text;
userInput = userInput.Replace(" ", ""); //remove spaces
if (userInput.Length == 0)
{
throw new ArgumentNullException();
}
var operation = new Operation();
var leftSide = true;
for (int i = 0; i < userInput.Length; i++)
{
if (numbers.Any(c => userInput[i] == c))
{
if (leftSide)
{
operation.LeftSide = AddNumberPart(operation.LeftSide, userInput[i]);
}
else
{
operation.RightSide = AddNumberPart(operation.RightSide, userInput[i]);
}
}
else if (operators.Any(c => userInput[i] == c))
{
if (!leftSide)
{
var operatorType = GetOperationType(userInput[i]);
if (operation.RightSide.Length == 0)
{
if (operatorType != OperartionType.Minus)
{
throw new InvalidOperationException();
}
operation.RightSide += userInput[i];
}
else
{
operation.LeftSide = operation.Calculate();
operation.operartionType = operatorType;
operation.RightSide = string.Empty;
}
}
else
{
var operatorType = GetOperationType(userInput[i]);
if (operation.LeftSide.Length == 0)
{
if (operatorType != OperartionType.Minus)
{
throw new InvalidOperationException();
}
operation.RightSide += userInput[i];
}
else
{
operation.operartionType = operatorType;
leftSide = false;
}
}
}
}
return(operation.Calculate());
}
catch (Exception e)
{
return(e.Message);
}
}