Casting string to Int32 errors

Question

I am trying to cast a string into an int and for some reason the following seems to work.

Dim theInt As Int32 = CInt("55e5")
Console.WriteLine("String to Int32: " & theInt)

I am having trouble understanding why it converts correctly and outputs 5500000

Yes, I didn't even recognize that the string was formatted for Scientific notation. — GER
– GER, Commented Oct 29, 2013 at 18:04
So I am clear, I did not want 550000. I was expecting to catch exceptions and warning users about input errors. — GER
– GER, Commented Oct 30, 2013 at 11:48

tymeJV · Accepted Answer · 2013-10-29 17:43:36Z

1

Its converting that e5 to scientific notation (think that's the proper term?), so its pushing the decimal place 5 times over, hence 5500000 (5 extra 0's)

answered Oct 29, 2013 at 17:43

tymeJV

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rheitzman · Accepted Answer · 2013-10-29 20:09:32Z

Where you expecting 55 as the answer? The old VB VAL() would return that.

I played with a custom .Net Val() for our code. In mostly deals with dollar signs, commas, (), but could be extended:

Public Function ValTest(ByVal value As String) As Double
    If String.IsNullOrEmpty(value) Then Return 0
    If IsNumeric(value) Then Return CDbl(value.Trim) ' IsNumeric and CDbl strip currency $ and comma, and support accounting negation e.g. ($23.23) = -23.23
    ' deal with case where leading/trailing non-numerics are present/expected
    Dim result As String = String.Empty
    Dim s As String = value.Trim
    If s.StartsWith("(") Then s.Replace("(", "-") ' leading ( = negative number from accounting - not supported by VB.Val()
    For Each c As Char In s
        If Char.IsNumber(c) OrElse "-.".Contains(c) Then
            result = (result + c)
        End If
    Next c
    If String.IsNullOrEmpty(result) Then
        Return 0
    Else
        Return CDbl(result)
    End If
End Function

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