Display line says index was out of range - vb.net

Question

There is a button that displays an item from an array by searching an input in another array. In this instance, I want to display an item from animalArray.
To do this, a user needs to input a certain name from the nameArray. Binary search, will compare the input and nameArray(middle). But when all that is done, when displaying the array using listbox it crashes and says "index was out of bounds of the array". Even though all items in all arrays has 9 items including 0.
binarySearch(nameArray, animalArray, InputBox("Enter Owner name", "Owner name"))
How to solve this?
Sub binarySearch(ByVal array1, ByVal array2, ByVal item)
Sort()
Dim low = 0
Dim high = 9
Dim middle As String
Dim subfindindex = -1
Do While low <= high And subfindindex = -1
middle = (low + high) \ 2
If array1(middle) = item Then
subfindindex = middle
Exit Do
End If
If middle > item Then
high = middle - 1
Else
low = middle + 1
End If
Loop
ListBox1.Items.Add(array2(subfindindex)) '<--- index was out of bounds of array
End Sub

Answer 1

Your main problem is that you're comparing a number to a name, and attempting to determine which is greater:
If middle > item Then
Instead, you'll want to compare the number (the value of the middle variable) to the index of the name in the name array.
That said, you'll get more mileage with this by using lists instead of arrays, and by descriptively naming and strongly typing your parameter variables. Here's the working code:
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim Animals As New List(Of String)
Dim Names As New List(Of String)
Animals.Add("Dog")
Animals.Add("Cat")
Animals.Add("Sheep")
Animals.Add("Goat")
Animals.Add("Chicken")
Animals.Add("Fish")
Animals.Add("Cow")
Animals.Add("Snake")
Animals.Add("Rabbit")
Animals.Add("Squirrel")
Names.Add("Jim")
Names.Add("Betty")
Names.Add("Frank")
Names.Add("Paul")
Names.Add("Susan")
Names.Add("Debbie")
Names.Add("Bob")
Names.Add("Tina")
Names.Add("Fred")
Names.Add("Bill")
Me.BinarySearch(Names, Animals, InputBox("Enter Owner name", "Owner name"))
End Sub
Sub BinarySearch(Names As List(Of String), Animals As List(Of String), Name As String)
Dim SubFindIndex As Integer
Dim Middle As Integer
Dim High As Integer
Dim Low As Integer
SubFindIndex = -1
High = 9
Low = 0
Do While Low <= High And SubFindIndex = -1
Middle = (Low + High) \ 2
If Names(Middle) = Name Then
SubFindIndex = Middle
Exit Do
End If
If Middle > Names.IndexOf(Name) Then
High = Middle - 1
Else
Low = Middle + 1
End If
Loop
Me.ListBox1.Items.Add(Animals(SubFindIndex))
End Sub
End Class
But there's a lot simpler way of accomplishing the same goal:
Sub BinarySearch2(Names As List(Of String), Animals As List(Of String), Name As String)
Dim Animal As String
Dim Index As Integer
Index = Names.IndexOf(Name)
Animal = Animals(Index)
Me.ListBox1.Items.Add(Animal)
End Sub
--EDIT--
Here's what you should see after entering a name from the list in the InputBox: