How to append an integer to an array in visual basic - vb.net

Question

I'm making a program that takes a sentence with no punctuation as an input, then searches for how many occurrences there are of a specific word.
Dim sntnce As String
Dim srchWord As String
Dim words As String()
Dim word As String
Dim count As Integer
Dim index As New System.Text.StringBuilder()
Console.WriteLine("Enter your sentence: ")
sntnce = Console.ReadLine()
sntnce = LCase(sntnce)
Console.WriteLine("Enter the word you want to find the position of: ")
srchWord = Console.ReadLine()
srchWord = LCase(srchWord)
words = sntnce.Split(New Char() {" "c})
Console.WriteLine(" ")
For Each word In words
If word = srchWord Then
index.Append(count)
count += 1
Else
count += 1
End If
Next
Console.WriteLine("Your word appears in the position(s)...")
Console.WriteLine(index)
Console.ReadLine()
The for loop takes the index of a word if found in a sentence and appends it to a string, but I would like to append it to an array so that the values for indexes can be outputted separately, however I can't find any solutions that help. How can I do this? Thanks

Answer 1

Arrays are of fixed size only. When dealing with collections that you want to add, remove or insert use List(Of T).
I think what you want is the following:
Sub Main()
Dim sntnce As String
Dim srchWord As String
Dim words As String()
Dim word As String
Dim count As Integer
Console.WriteLine("Enter your sentence: ")
sntnce = Console.ReadLine()
sntnce = LCase(sntnce)
Console.WriteLine("Enter the word you want to find the position of: ")
srchWord = Console.ReadLine()
srchWord = LCase(srchWord)
words = sntnce.Split(New Char() {" "c})
Console.WriteLine(" ")
' Create an expandable list of integers 'index_list'
Dim index_list As New List(Of Integer)
For index As Integer = 1 To words.Length
' It's recommened to use `Equals()` for string equality instead of `=`
' Arrays in VB.NET are 0-based so the i-th elements is located in `list(i-1)`
If words(index - 1).Equals(srchWord) Then
' Add index to list if there is a match
index_list.Add(index)
End If
Next
' Create a fixed array of strings to hold the character representation of the integer index array.
' Since I know the size I can use an array instead of a list.
Dim index_list_string As String() = New String(index_list.Count) {}
For index As Integer = 1 To index_list.Count
' One to one mapping of integer to string
index_list_string(index - 1) = index_list(index - 1).ToString()
Next
Console.WriteLine("Your word appears in the position(s)...")
' Take the array of strings and combine it into one string with commas in between using the `.Join()` function
' For example `{"A","B","C"} => "A, B, C"
Console.WriteLine(String.Join(", ", index_list_string))
Console.ReadLine()
End Sub