The EquityOption Class

   A Visual Basic "Class" is a way to keep all information about a type of object together, and also a way to return whatever information about an object you need.

     For instance, if you had a program that needed information about a lot of rectangles, to do it without using a class you would enter the height and width of each rectangle, and every time you needed to know the area of a rectangle you would need to do a calculation like "rectangle1 area = rectangle1 height x rectangle1 width".

     But by using a class, you can put functions you need inside the class, such as "area = height x width". Then every time you need the area of a rectangle, you can just refer to the function in the class, such as by using "rectangle1.area".

     This saves a lot of repetitive coding and calculations. In our project, an "option" is a type of object we need to store and retrieve a lot of details about, such as "long or short", "put or call", price, strike, etc. Making a class for options will therefore make our code cleaner, easier to use, and easier to understand.

     Using a class may seem like a little overkill right now, since our calculator project only uses one option "leg". But we will be building on our calculator later by adding three more option legs, and putting the details about options in a class will save a lot of repetitive coding.

     We have built the class for you. All you need to do is copy and paste. But first, you need to make a special place to put it.

     In your Visual Basic project, look to the upper right of your screen and find the "Solution Explorer" window. You should see the name of the project, "Option Calculator", in bold. Right-click on "Option Calculator", click on "Add", and then "Class".

     A window will open and suggest the name "Class1.vb" at the bottom. Change the name to "EquityOption.vb" and click the "Add" button.

     A new code space will open, with "Public Class EquityOption" at the top, and "End Class" at the bottom.

     Now, simply copy all of the code below, and paste it to the space between "Public Class EquityOption" and "End Class".

Dim otype As String Dim numc As Integer Dim entry, exp As Date Dim stock, strike, oprice, ivol, intrate, div As Single Dim include As Boolean Public Sub New(ByVal optiontype As String, ByVal numcontracts As Integer, ByVal entrydate As Date, ByVal stockprice As Single, ByVal strikeprice As Single, ByVal expiration As Date, ByVal price As Single, ByVal iv As Single, ByVal included As Boolean, ByVal interestrate As Single, ByVal dividends As Single) otype = optiontype numc = numcontracts entry = entrydate .Date stock = stockprice strike = strikeprice exp = expiration.Date oprice = Math.Round(price, 2) ivol = Math.Round(iv / 100, 2) include = included intrate = interestrate div = dividends End Sub Function price() As Single oprice = optionvalue(stock, strike, timeleft(entry, exp), intrate, ivol, div, otype) If oprice < 0.01 Then Return 0.01 Else Return Math.Round(oprice, 2) End If End Function Function volatility() As Single ivol = findIV(stock, strike, timeleft(entry, exp), intrate, div, oprice, otype) If ivol < 0.01 Then Return 0.01 Else Return Math.Round(ivol, 2) End If End Function Function totalvalue(ByVal displayprice As Decimal) As String If include = True Then Return FormatCurrency(valuesign() * displayprice * 100 * numc) Else Return FormatCurrency(0) End If End Function Function colorize() As Color If include = True Then If otype.Contains("Long") Then Return Color.Pink Else Return Color.LightGreen End If Else Return Color.Gray End If End Function Function expirationafterentry() As Boolean 'need to check all legs included or not, otherwise could get errors when figuring price If DateDiff(DateInterval.Day, entry, exp) > 0 Then Return True Else Return False End If End Function Function valuesign() As Integer If otype.Contains("Long") Then Return 1 Else Return -1 End If End Function

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