CSC 162

Visual Basic I Programming

Array Parameters and Sorting• Array Parameters

– Entire Arrays– Individual Elements

• Sorting– Bubble Sort

Array Parameters

• When arrays are passed to procedures, they must be passed ByRef.– Visual Basic makes this a requirement since copying

large arrays could take up too much room in memory.

Array Parameters

• Array parameters are not specified with a size, since they are passed ByRef.

Private Sub PrintNums(ByRef intNums() As Integer)

Dim intCounter As Integer

For intCounter = LBound(intNums) To UBound(intNums)

Print intNums(intCounter)

Next intCounter

End Sub

Array Parameters

• When arrays are passed into a procedure, the size is also not specified, since they are passed ByRef.

Dim intValues(1 To 100) As Integer

.

.

.

Call PrintNums(intValues())

Array Parameters• However, individual elements of the array are passed just

like any single value.

Private Sub PrintValue(ByVal intValue As Integer)

Print "The selected value is " & intValue

End Sub

Dim intNumbers(1 To 50) As Integer

.

.

.

Call PrintValue(intNumbers(20))

Bubble Sort• Arrays can be sorted in two ways:

– Ascending (1 100, A Z, etc.)

– Descending (100 1, Z A, etc.)

• Array functions:– Starting index (lower bound):LBound()– Ending index (upper bound): UBound()

Lab AssignmentWrite a program that will do the following: 1. Put 20 random (integer) numbers with a range of 1 to 100

into an array of size 20. 2. Sort the array in descending order.*3. Display the entire sorted array in a ListBox.

* Use the Bubble Sort algorithm, but put it into a sub procedure called DescendingSort.

Programming Assignment 5Due Monday, November 10 / Tuesday, November 11Page 241 #6.18Page 241 #6.19