public double Evaluate()
{
double x = leftOperand.Evaluate();
double y = rightOperand.Evaluate();
if (operationChar == '+')
{
return(x + y);
}
if (operationChar == '-')
{
return(x - y);
}
if (operationChar == '*')
{
return(x * y);
}
if (operationChar == '/')
{
return(x / y);
}
throw new Exception("Unknown Operation!");
}
