Public Class account
    Private id As String
    Private name As String
    Private password As String
    Private balance As Double

    ' don't really know what to put in for a default account
    Public Sub New()
        name = "unknown"
        id = "invalid"
        password = "password"
        balance = 0
    End Sub

    ' everything but balance - balance defaults to 0
    Public Sub New(ByVal acctId As String, ByVal acctName As String, ByVal pw As String)
        name = acctName
        id = acctId
        password = pw
        balance = 0
    End Sub

    ' all needed info supplied
    Public Sub New(ByVal acctId As String, ByVal acctName As String, ByVal pw As String, ByVal bal As Double)
        name = acctName
        id = acctId
        password = pw
        balance = bal
    End Sub

    ' could probably also use ones where account number and/or pin are generated rather than passed
    ' but don't need them for this example

    '' define properties, starting with acctNum
    Public Property acctNum()
        Get
            Return id
        End Get
        Set(ByVal Value)
            ' in a simple example we don't validate this
            ' in the real world there is probably a set of rules for what makes for a valid acct num
            ' probably also should check to make sure the acct num doesn't already exist
            id = Value
        End Set
    End Property

    Public Property custName()
        Get
            Return name
        End Get
        Set(ByVal Value)
            ' I don't think there is really a way to validate a customer name
            name = Value

        End Set
    End Property

    Public Property PIN()
        Get
            Return password
        End Get
        Set(ByVal Value)
            ' for simple example accept anything as valid
            ' in real world, may have rules
            password = Value
        End Set
    End Property


    Public Property bal()
        Get
            Return balance
        End Get
        Set(ByVal Value)
            ' I really don't want to make this available for anybody to change - I want them to go through, deposit, withdraw etc
            ' so I almost made the property private
            ' I want to allow negative balance because if the person overdraws the account, I don't want them to get away with it
            balance = Value

        End Set
    End Property

    '' now - more interesting methods
    ' Deposit - add money to the account - return true if successful, false otherwise
    '    problem would be if negative amount passed - don't want to allow withdrawl by calling
    '    deposit with negative amount
    Public Function deposit(ByVal amt As Double) As Boolean
        If amt <= 0 Then
            Return False
        Else
            balance = balance + amt
        End If
        Return True
    End Function

    ' withdraw - subtract money from account - return true if successful, false otherwise
    '    problem if amt is not positive or if not enough money in account
    '    if you want to allow overdraft, call forceWithdraw below
    Public Function withdraw(ByVal amt As Double) As Boolean
        If amt <= 0 Then
            Return False
        ElseIf amt > balance Then
            Return False
        Else
            balance = balance - amt
            Return True
        End If
    End Function


    ' force withdraw - subtract money from account, even allowing overdraft  - return true if successful, false otherwise
    '    problem if amt is not positive  
    Public Function forceWithdraw(ByVal amt As Double) As Boolean
        If amt <= 0 Then
            Return False
        Else
            balance = balance - amt
            Return True
        End If
    End Function

    ' account inquiry 
    ' my way to allow controlled access to account balance 
    ' somebody can see it - but to change it, they must deposit or withdraw
    Public Function acctInq() As Double
        Return balance
    End Function

    ' check of whether a passed string matches the account id of an account
    ' provided to push more capability into the class
    Public Function matchAcctNum(ByVal toMatch As String) As Boolean
        If id = toMatch Then
            Return True
        Else
            Return False
        End If
    End Function

    ' check out whether an account number and pin both match the passed values
    Public Function matchAcctNumNPIN(ByVal acct As String, ByVal pn As String) As Boolean
        If acct = id AndAlso pn = password Then
            Return True
        Else
            Return False
        End If
    End Function

    ' check out whether the current account and a passed account match on both acctnum and pin
    Public Function matchAccounts(ByVal toCompare As account) As Boolean
        If id = toCompare.id AndAlso password = toCompare.password Then
            Return True
        Else
            Return False
        End If
    End Function

    ' check out whether the current account and a passed account match on all attributes
    Public Function identicalMatchAccounts(ByVal toCompare As account) As Boolean
        If id = toCompare.id AndAlso password = toCompare.password _
            AndAlso name = toCompare.name AndAlso balance = toCompare.balance Then
            Return True
        Else
            Return False
        End If
    End Function

    ' provides acctnum and name - nothing of privacy concern (pin and balance)
    Public Function privacyToString()
        Return id & "," & name
    End Function


End Class