Computer Programming Concepts and Visual Basic David I. Schneider

Houston 3.7 $31,488 67 8
Los Angeles 14.5 $36,711 59 8
New York 18.1 $38,445 73 11
Philadelphia 5.9 $35,797 70 8
San Francisco 6.3 $41,459 60 11
Washington 3.9 $47,254 32 17
Note: Column 4 gives the percentage of residents who were born in their current state of residence. Column
5 gives the percentage of residents age 25 or older with a graduate or professional degree.
Source: The 1990 Census
SOLUTION:
Data are read from a file into parallel arrays by the Form_Load event procedure. When cmdDisplayStats
is clicked, the collection of parallel arrays is sorted based on the array pop( ). Each time two items are
interchanged in the array pop( ), the corresponding items are interchanged in each of the other arrays. This
way, for each city, the items of information remain linked by a common subscript.
Dim city(1 To 10) As String, pop(1 To 10) As Single, income(1 To 10) As Single
Dim natives(1 To 10) As Single, advDeg(1 To 10) As Single
Private Sub cmdDisplayStats_Click()
Call SortData
Call ShowData
End Sub
Private Sub Form_Load()
Dim i As Integer
‘Assume the data for city name, population, medium income, % native,
‘and % advanced degree have been placed in the file “CITYSTAT.TXT”
‘(First line of file is “Boston”, 4.2, 40666, 73, 12)
Open “CITYSTAT.TXT” For Input As #1
For i = 1 To 10
Input #1, city(i), pop(i), income(i), natives(i), advDeg(i)
Next i
Close #1
End Sub
Private Sub ShowData()
Dim i As Integer
‘Display ordered table
picTable.Cls
picTable.Print , “Pop. in”, “Med. income”, “% Native”, “% Advanced”
picTable.Print “Metro Area”, “millions”, “per hsd”, “to State”, “Degree”
picTable.Print For i = 1 To 10
picTable.Print city(i); Tab(16); pop(i), income(i), natives(i), advDeg(i)
Next i
End Sub
Private Sub SortData()
Dim passNum As Integer, index As Integer
‘Bubble sort table in descending order by population
For passNum = 1 To 9
For index = 1 To 10 - passNum
If pop(index) < pop(index + 1) Then Call
SwapData(index)
End If
Next index
Next passNum
End Sub
Sorting and Searching 187