Computer Programming Concepts and Visual Basic David I. Schneider

110 Computer Programming Concepts and Visual Basic
This block searches for the first true condition, carries out its action, and then skips to the
statement following End If. If none of the conditions is true, then Else’s action is carried out.
Execution then continues with the statement following the block. In general, an If block can
contain any number of ElseIf clauses. As before, the Else clause is optional.
EXAMPLE 5
Redo Example 1 so that if the two numbers are equal, the program so reports.
SOLUTION:
Private Sub cmdFindLarger_Click()
picResult.Cls
If Val(txtFirstNum.Text) > Val(txtSecondNum.Text) Then
picResult.Print “The larger number is “; txtFirstNum.Text
ElseIf Val(txtSecondNum.Text) > Val(txtFirstNum.Text) Then
picResult.Print “The larger number is “; txtSecondNum.Text
Else
picResult.Print “The two numbers are equal.”
End If
End Sub
[Run, type 7 into both text boxes, and press the command button.]
If blocks allow us to define functions whose values are not determined by a simple formula.
The function in Example 6 uses an If block.
EXAMPLE 6
The Social Security or FICA tax has two components—the Social Security benefits tax, which in 1999 is
6.2 percent on the first $72,600 of earnings for the year, and the Medicare tax, which is 1.45 percent of
earnings. Write a program to calculate an employee’s FICA tax for the current pay period.
SOLUTION:
Object Property Setting
frmFICA Caption FICA Taxes
lblToDate Caption Total earnings for this year prior to the
current pay period
Alignment Right Justify
txtToDate Text (blank)
lblCurrent Caption Earnings for the current pay period
Alignment Right Justify
txtCurrent Text (blank)
cmdCalculate Caption Calculate FICA Taxes
picTax
Private Sub cmdCalculate_Click()
Dim FicaTaxes As Single
FicaTaxes = FICA(Val(txtToDate.Text), Val(txtCurrent.Text))