Computer Programming Concepts and Visual Basic David I. Schneider

End Sub
[Run, type White Sox into the text box, and click the command button.]
We could have written the program in Example 2 with a For...Next loop beginning For
n = 1 To 5. However, such a loop would unnecessarily search the entire list when the soughtafter
item is found early. The wasted time could be significant for a large array.
In some applications, arrays are needed only temporarily to help a procedure complete
a task. Visual Basic also allows us to create array variables that are local to a specific procedure
and that exist temporarily while the procedure is executing. If the statement
Dim arrayName(1 To n) As varType
is placed inside an event procedure or general procedure, then space for n subscripted variables
is set aside in memory each time the procedure is invoked and released when the procedure is
exited.
In Example 1, values were assigned to the elements of the array with assignment statements.
However, data for large arrays are more often stored in a data file and read with Input
# statements. Example 3 uses this technique. Also, because the task of the program is likely
to be performed only once during a run of the program, a local array is used.
EXAMPLE 3
Table 6.1 gives names and test scores from a mathematics contest given in 1953. Write a program to display
the names of the students scoring above the average for these eight students.
TABLE 6.1
The Top Scores on the Fourth Annual Mathematics Contest Sponsored by the
Metropolitan NY Section of the MAA
Richard Dolen 135 Paul H. Monsky 150
Geraldine Ferraro 114 Max A. Plager 114
James B. Fraser 92 Robert A. Schade 91
John H. Maltby 91 Barbara M. White 124
Source: The Mathematics Teacher, February 1953.
SOLUTION:
The following program creates a string array to hold the names of the contestants and a numeric array to
hold the scores. The first element of each array holds data for the first contestant, the second element of
each array holds data for the second contestant, and so on. See Figure 6-3. Note that the two arrays can
be dimensioned in a single Dim statement by placing a comma between the array declarations.
Private Sub cmdShow_Click()
Dim total As Integer, student As Integer, average As Single
’Create arrays for names and scores
Dim nom(1 To 8) As String, score(1 To 8) As Integer
‘Assume the data has been placed in the file “SCORES.TXT”
‘(The first line of the file is “Richard Dolen”, 135)
Open “SCORES.TXT” For Input As #1
For student = 1 To 8
Input #1, nom(student), score(student)
Next student
Close #1
Creating and Accessing Arrays 165