Class Notes: 06/21/06
Assignment: Case Study -Payroll System Phase 4: Decision-Making
4B) Determine an additional tax rate based on marital status:
1) Declare marital status as a number (integer).
1=Single 2=Married 3=Head of Household
An additional 5% will be added to the tax rate of s single person subtract 5% if head of household.
2) Declare marital status as character
(working with either letters M, S, H, or character digits 1, 2, 3)
3) Program should accept either upper case or
lower case letters for marital status (e.g. accept M or m).
What do we need in order to calculate tax rate?
a) Gross pay
b) Marital Status
(Take a look at page 115 for a similar problem)
Instead of choice we’ll call it marital status by either textbox, inputbox
or radio button.
Dim status as integer
status = textbox1.text
if (status = 1) then
msgbox(“YOUR STATUS IS SINGLE”)
else if (status = 2) then
msgbox(“YOUR STATUS IS MARRIED”)
else if (status = 3) then
msgbox(“YOUR STATUS IS HEAD OF HOUSEHOLD”)
else
msgbox(“ERROR IN ENTRY”)
end if
Using variable as “char”
Now, if we want to enter uppercase letters for status we will need to add
another piece of code.
Dim status As
Char
status = TextBox1.Text
If (status = "1") Then
MsgBox("YOUR STATUS IS SINGLE")
ElseIf (status = "2") Then
MsgBox("YOUR STATUS IS MARRIED")
ElseIf (status = "3") Then
MsgBox("YOUR STATUS IS HEAD OF HOUSEHOLD")
ElseIf (status = "s") Then
MsgBox("YOUR STATUS IS SINGLE")
ElseIf (status = "m") Then
MsgBox("YOUR STATUS IS MARRIED")
ElseIf (status = "h") Then
MsgBox("YOUR STATUS IS HEAD OF HOUSEHOLD")
ElseIf (status = "S") Then
MsgBox("YOUR STATUS IS SINGLE")
ElseIf (status = "M") Then
MsgBox("YOUR STATUS IS MARRIED")
ElseIf (status = "H") Then
MsgBox("YOUR STATUS IS HEAD OF HOUSEHOLD")
Else
MsgBox("ERROR IN ENTRY")
End If
Second part of Question # 1
Dim status As
Char
Dim taxrate As Double
status = TextBox1.Text
taxrate = TextBox2.Text
If (status = "1") Then
MsgBox("YOUR STATUS IS SINGLE")
taxrate = taxrate + 0.05
TextBox2.Text = taxrate
ElseIf (status = "2") Then
MsgBox("YOUR STATUS IS MARRIED")
ElseIf (status = "3") Then
MsgBox("YOUR STATUS IS HEAD OF HOUSEHOLD")
taxrate = taxrate - 0.05
TextBox2.Text = taxrate
ElseIf (status = "s") Then
MsgBox("YOUR STATUS IS SINGLE")
ElseIf (status = "m") Then
MsgBox("YOUR STATUS IS MARRIED")
ElseIf (status = "h") Then
MsgBox("YOUR STATUS IS HEAD OF HOUSEHOLD")
ElseIf (status = "S") Then[k;
MsgBox("YOUR STATUS IS SINGLE")
taxrate = taxrate + 0.05
TextBox2.Text = taxrate
ElseIf (status = "M") Then
MsgBox("YOUR STATUS IS MARRIED")
ElseIf (status = "H") Then
MsgBox("YOUR STATUS IS HEAD OF HOUSEHOLD")
taxrate = taxrate - 0.05
TextBox2.Text = taxrate
Else
MsgBox("ERROR IN ENTRY")
End If
Example of Select Statement.
You can also use the SELECT statement if you want to select one of many blocks of code to execute:
|
select case payment case "Cash" msgbox "You are going to pay cash" case "Visa" msgbox "You are going to pay with visa" case "AmEx" msgbox "You are going to pay with American Express" case Else msgbox "Unknown method of payment" end select |
This is how it works: First we have a single expression (most often a variable), that is evaluated once. The value of the expression is then compared with the values for each Case in the structure. If there is a match, the block of code associated with that Case is executed.
Another example of Select Case taken from: http://theopensourcery.com/vb05tut.htm
One of the
statements that Visual Basic lacks is the Continue statement. There are times in
the middle of a loop when you want to stop testing and just go to the next
iteration in the loop. One can approximate this with nested Ifs but the logic of
the nesting can quickly become quite complicated and obscure to follow. Visual
Basic does not have a Continue statement, but its very powerful Select Case
conditional statement will fill in quite well in many cases. The best way to
show how a Select Case works is to give an example.
Select Case iswitch
Case 1
'Print a short report
itype = "short"
call PrintReport(itype)
Case 2,3,4 'Print a long,
detailed report
itype="long"
call LongReport(itype,isw)
Case 5 'Graph the output
call GraphReport()
Else Case 'All other
cases or values of iswitch are an error
MsgBox iswitch + " is not expected, Error"
End Select
Array:
Array comes from the word
arrangement.