Convert string array to int array

Question

I have tried a couple different ways and cannot seem to get the result I want using vb.net.

I have an array of strings. {\"55555 \",\"44444\", \" \"}

I need an

Answer 1

Everything is much easier ))

Dim NewIntArray = YouStringArray.Select(Function(x) CInt(x)).ToArray

Answer 2

You can use the List(Of T).ConvertAll method:

Dim stringList = {"123", "456", "789"}.ToList
Dim intList = stringList.ConvertAll(Function(str) Int32.Parse(str))

or with the delegate

Dim intList = stringList.ConvertAll(AddressOf Int32.Parse)

If you only want to use Arrays, you can use the Array.ConvertAll method:

Dim stringArray = {"123", "456", "789"}
Dim intArray = Array.ConvertAll(stringArray, Function(str) Int32.Parse(str))

Oh, i've missed the empty string in your sample data. Then you need to check this:

Dim value As Int32
Dim intArray = (From str In stringArray
               Let isInt = Int32.TryParse(str, value)
               Where isInt
               Select Int32.Parse(str)).ToArray

By the way, here's the same in method syntax, ugly as always in VB.NET:

Dim intArray = Array.ConvertAll(stringArray,
                        Function(str) New With {
                            .IsInt = Int32.TryParse(str, value),
                            .Value = value
                        }).Where(Function(result) result.IsInt).
                Select(Function(result) result.Value).ToArray

Answer 3

Maybe something like this:

dim ls as new List(of string)()
ls.Add("55555")
ls.Add("44444")
ls.Add(" ")
Dim temp as integer
Dim ls2 as List(Of integer)=ls.Where(function(x) integer.TryParse(x,temp)).Select(function(x) temp).ToList()

Answer 4

My $.02

    Dim stringList() As String = New String() {"", "123", "456", "789", "a"}
    Dim intList() As Integer

    intList = (From str As String In stringList
               Where Integer.TryParse(str, Nothing)
               Select (Integer.Parse(str))).ToArray

Answer 5

Maybe a few more lines of code than the other answers but...

    'Example assumes the numbers you are working with are all Integers.
    Dim arrNumeric() As Integer

    For Each strItemInArray In YourArrayName

        If IsNumeric(strItemInArray) Then

            If arrNumeric Is Nothing Then

                ReDim arrNumeric(0)
                arrNumeric(0) = CInt(strItemInArray)

            Else

                ReDim Preserve arrNumeric(arrNumeric.Length)
                arrNumeric(arrNumeric.Length - 1) = CInt(strItemInArray)

            End If

        End If

    Next

Answer 6

You can use the Array.ConvertAll method:

    Dim arrStrings() As String = {"55555", "44444"}
    Dim arrIntegers() As Integer = Array.ConvertAll(arrStrings, New Converter(Of String, Integer)(AddressOf ConvertToInteger))


    Public Function ConvertToInteger(ByVal input As String) As Integer
        Dim output As Integer = 0

        Integer.TryParse(input, output)

        Return output
    End Function