Computer Programming Concepts and Visual Basic David I. Schneider

138 Computer Programming Concepts and Visual Basic
Else
picNumber.Print “Name not found.”
End If
End Sub
[Run, type Grover into the text box, and press the command button.]
■ COUNTERS AND ACCUMULATORS
A counter is a numeric variable that keeps track of the number of items that have been
processed. An accumulator is a numeric variable that totals numbers.
EXAMPLE 3
The following program counts and finds the value of coins listed in a file.
COINS.TXT contains the following entries: 1, 1, 5, 10, 10, 25
Object Property Setting
frmCoins Caption Coins
cmdAnalyze Caption Analyze Change
picValue
Private Sub cmdAnalyze_Click()
Dim numCoins As Integer, sum As Single, value As Single
Open “COINS.TXT”For Input As #1
numCoins = 0
sum = 0
Do While Not EOF(1)
Input #1, value
numCoins = numCoins + 1
sum = sum + value
Loop
picValue.Cls
picValue.Print “The value of the”; numCoins; “coins is”; sum; “cents.”
Close #1
End Sub
[Run, and press the command button.]
The value of the counter, numCoins, was initially 0 and changed on each execution of the loop
to 1, 2, 3, 4, 5, and finally 6. The accumulator, sum, initially had the value 0 and increased with
each execution of the loop to 1, 2, 7, 17, 27, and finally 52.